worksheet to help prepare for the first test
TRANSCRIPT
Worksheet to help prepare for the first test and Chemistry TEKS 2 and 4
List of things you should know: a) What is chemistry? b) What is the appropriate procedures to ensure safety in the lab and classroom?
i) What should you do in case of a fire? ii) What should you do in case of a chemical spill? iii) What should you do in case of broken glass? iv) What should you do to prevent damage to your clothes? v) What should you do to prevent damage to your skin or eyes? vi) What should you do to prevent fire, spills and broken equipment?
c) What is matter? i) What are the states of matter
(1) How do the states of matter differ in temperature, spacing, energy, shape, and volume?
(2) How do intrinsic properties differ from extrinsic properties? (be able to list examples)
(3) Explain density and how it is determined and used (4) Explain phosphorescence and fluorescence
ii) Similarities and differences in elements, molecules, compounds, and mixtures iii) What is a concentration and how is it used?
d) Explain dimensional analysis i) What are the major units of measure for mass, time, volume and length in both metric
and English systems. ii) Convert between English and metric units iii) Convert between units within either English or metric systems.
e) Explain the difference between accuracy and precision f) Identify and place in 3 dimensional space the components of an atom.
i) What is the relative sizes of electrons, protons and neutrons? ii) What are the differences in charge for electrons, protons and neutrons? iii) How does mass of electrons differ from that of Protons or neutrons. iv) How is atomic number, atomic mass, charge and number of atoms present get shown
in chemical shorthand? v) How is phosphorescence and fluorescence related to atom structure
Example questions: 1) Compounds consist of two or more elements
a) combined in definite proportions by mass; b) mixed together; c) combined in varying proportions; d) combined physically.
2) 5A prediction is a scientific hypothesis only if it
a) can be tested by some planned activity; b) is based on experience; c) will come true in the future; d) states a generalization based on established fact.
3) Because scientists assume that there is a cause behind each occurrence, they are able to
a) make predictions about natural events; b) control when most natural events will occur; c) change most natural events; d) make sure most natural events do not take place.
4) Three different observers measure the melting temperature of a substance and agree on the
same value, but the value they obtain does not agree with the accepted value. Their measurements can be described as a) both accurate and precise. b) neither accurate nor precise. c) precise but not accurate. d) accurate but not precise.
5) Which of the following statements is not an observation? a) The cat has soft fur. b) The dog has sharp claws. c) The duck’s eyes are gray. d) The tiger is more attractive than the alligator.
6) You see a friend’s car in front of a restaurant. If you assume your friend is in the restaurant,
you are making a(n) a) decision; b) theory; c) inference; d) law; e) observation.
7) After his first attempt to solve a problem, a scientist usually
a) reports his conclusions to other scientists; b) rechecks his work; c) writes articles for scientific journals; d) proceeds to find new and different problems.
8) In questioning a person’s claims about a scientific matter, the most scientific attitude is to say
a) “I don’t believe.” b) “Describe the evidence for your position.” c) “What authority supports your position?” d) “How do your results compare with those of other investigators?”
9) The temporary answer that a scientist uses to guide an experiment is a
a) collection; b) law; c) record; d) hypothesis; e) all of these.
10) Scientists do not
a) search for evidence; b) have a good imagination; c) jump to conclusions; d) test a hypothesis; e) share information with other researchers.
11) Scientific theories
a) always change; b) never change; c) change when new evidence is found; d) always become laws; e) none of these.
12) In drawing a scientific conclusion based on data collected by random sampling, scientists are
aware that the conclusion a) is tentative and may change as further data are obtained. b) is true until proven incorrect. c) should be withdrawn if others report contradictory results. d) holds only for the sample which furnished the data.
13) Scientists communicate their findings to other scientists because
a) they are proud of their work; b) they wish to gain fame; c) other scientists may recheck their work; d) an experiment is not finished until its results are announced.
14) A scientist’s “educated guess” about a problem is usually called
a) a law; b) a fact; c) an opinion; d) an hypothesis; e) a principle.
15) Which of these examples best illustrate the “if – then” reasoning of science? If the
hypothesis is true, a) then society should take action; b) this action should clear up the mystery; c) the basic strategy will advance our argument; d) this specific result or event will support it.
16) Which one of the following describes the process of science?
a) unorganized b) ongoing c) static d) inconsistent e) none of these
17) Which one of the following is characteristic of a scientific theory?
a) changeable b) proven c) permanent d) untested e) none of these
18) What can be gained in a systematic manner using scientific methods?
a) processes b) information c) models d) controls e) none of these
19) Which of the following is not an aspect of the scientific method?
a) making judgments based on experience or observation
b) maintaining a detached and impersonal approach
c) carrying out activities in an organized manner
d) establishing absolute truths 20) What is the major purpose of laboratory work in scientific research?
a) To verify previous work b) To demonstrate known facts c) To investigate questions d) To reach final conclusions
21) Which one of the following is an observation rather than an interpretation?
a) The candle wax is changed to soot.
b) The top of the candle becomes wet with a colorless wax.
c) The candle burns to produce carbon dioxide and water.
d) The burning candle makes little or no sound.
e) The candle is made up of carbon and hydrogen.
22) Which of the following is an observation rather than an interpretation?
a) The candle wax is changed soot.
b) The candle burns to produce carbon dioxide and water.
c) The wick is made of three strands of string.
d) The candle is made of carbon and hydrogen.
e) The top of the candle becomes wet with a colorless wax.
23) Which of the following is an interpretation rather than an observation?
a) The candle wax is changed into soot.
b) The burning gives off no smell.
c) The wick is white were it emerges from the candle.
d) The candle is made of a white solid.
e) The candle is about 3/4 inch in diameter. 24) 7The Law of Definite Proportions applies to the definite composition by mass of
a) atoms; b) elements; c) compounds; d) mixtures.
25) Two solid substances that have been stirred together but not chemically combined form a(n) a) element;
b) compound;
c) mixture;
d) suspension;
e) solvent.
26) All of the following are examples of extensive properties except
a) temperature;
b) volume;
c) weight;
d) mass.
27) Lead weighs 11.34 grams per cubic centimeter. This statement represents lead’s
a) shape; b) mass; c) hardness; d) state; e) density.
28) Which statement is correct for water?
a) It is not an element because it can exist in three states. b) It is a compound because all samples of water are alike. c) It is not a compound because its properties are different from its elements’ properties. d) It is not a mixture because it has a definite composition.
29) The smallest particle of an element which can enter into combination with other elements is
a) an atom; b) a molecule; c) a crystal; d) a macromolecule.
30) The atmosphere consists almost entirely of
a) hydrogen and oxygen; b) carbon dioxide; c) water and oxygen; d) carbon dioxide and oxygen; e) nitrogen and oxygen.
31) Which property would be most helpful in identifying a substance?
a) mass b) state c) volume d) melting point e) quantity
32) Measurements made during an experiment are what kind of observations?
a) qualitative b) variable c) quantitative d) model e) none of these
33) Heating a substance
a) never causes a chemical change;
b) may cause a chemical change;
c) always causes a chemical change;
d) has nothing to
e) do with chemical changes.
34) Air is a mixture because it
a) is colorless; b) is odorless; c) does not have a uniform composition; d) can be compressed.
35) Which is characteristic of mixtures?
a) Definite composition is present. b) Always have two phases present c) Components must be elementary. d) Components must be compounds e) Components can be separated by physical means.
36) A reaction in which heat is given off is called:
a) exothermic;
b) endothermic;
c) fractional;
d) caloric.
37) A material that readily transmit heat and electricity is
a) silicon; b) copper; c) plastic; d) an insulator; e) amorphous.
38) A mixture
a) consists only of compounds;
b) consists only of elements;
c) may consist of elements and compounds;
d) never consists of both elements and compounds.
39) A substance that is made up of more than one kind of molecule is called a(n) a) element; b) compound; c) mixture; d) atom.
40) A mixture consists of substances associated in a) definite proportions; b) equal proportions; c) any proportions; d) chemical combinations.
41) Photosynthesis is an example of a chemical change brought about by
a) heat; b) light; c) solution in water; d) electricity; e) none of these.
42) Which of the following is a unit of area?
a) meter
b) cm2
c) cm3
d) liter
e) none of these
43) The SI unit for measuring pressure is the a) pascal; b) joule; c) newton; d) watt; e) liter.
44) The SI unit for measuring force is the a) watt;
b) newton;
c) pascal;
d) joule;
e) none of these.
45) The SI unit for measuring energy is the
a) pascal; b) newton; c) joule; d) watt; e) gram.
46) Water in going through the three physical states would normally undergo
a) a change in mass. b) no energy changes. c) a change in weight. d) a change in density. e) a change in composition.
47) Factors that can change during an experiment are call
a) conclusions; b) standards; c) technology; d) laws; e) variables.
48) In addition to volume, which property of matter must be known to calculate mass?
a) index of refraction b) molecular weight c) specific heat d) viscosity e) density
49) A cube has a volume of 8.0 cm3
and a mass of 21.6 grams. The density of the cube, in grams per cubic centimeter, is best expressed as a) 2.7; b) 2.15; c) 0.37; d) 0.73; e) 0.98.
50) The property of a gas usually expressed in the units grams-per-liter, is the a) specific gravity; b) mole; c) molar volume; d) density.
51) Taking an object from Earth to Mars would most likely affect the object’s a) volume;
b) density;
c) mass;
d) shape;
e) weight.
52) The science dealing with the composition of materials and the changes in composition which
these materials undergo is
a) biology;
b) chemistry;
c) physics;
d) math.
53) Which does not belong?
a) boiling
b) melting
c) freezing
d) burning
e) none of these
54) Air, water, and rock are examples of
a) liquids; b) solids; c) gases; d) matter; e) equilibrium.
55) In general, when elements combine chemically, a) they retain all their original properties; b) a mixture results; c) new substances with new and different properties are formed; d) solutions are formed.
56) If the force of gravitational attraction of the earth were twice as strong as it is, a person
would weigh approximately a) half as much as he presently weighs; b) the same as he presently weighs; c) twice as much as he presently weighs; d) four times as much as he presently weighs.
57) The mass of an object a) is a measure of the gravitational force pulling the object toward the earth.
b) is a measure of the amount of matter in the object.
c) is a measure of the space occupied by the object.
d) varies with the altitude above the surface of the earth.
58) Chemistry is chiefly concerned with the study of changes in matter involving
a) forces; b) heat; c) composition; d) electricity.
59) Chemistry is the study of
a) electrons and protons;
b) explosives;
c) the production of new substances;
d) the properties, structure, and
e) changes of matter. 60) Generally, when a solid substance is heated it volume increases. The effect of increased
temperature on the density of the substance then is
a) to leave the density unchanged.
b) to increase the density.
c) t o decrease the density.
d) impossible to predict.
61) Which substance cannot be decomposed by a chemical change?
a) carbon dioxide
b) potassium chlorate
c) water
d) copper
62) When several substances are placed together but do not combine chemically, they form a(n)
a) compound;
b) mixture;
c) element;
d) molecule;
e) crystal.
63) Which of the following is not a general property of matter? a) mass b) volume c) density d) flammability
64) Iron is more dense than water because iron a) is a solid; b) contains more matter per cubic centimeter; c) has a larger volume; d) has the same composition throughout; e) is an element.
65) A difference between mass and weight is that
a) the weight of an object does not depend on the amount of material present. b) weight units are different. c) the mass of an object is different on different planets. d) the mass of an object is fixed although its weight may vary with the gravitational force
acting on it. 66) Four liquids have the following densities: A = l.0 g/ml, B = 0.8 g/ml, C = 0.6 g/ml, D = l.2
g/ml. In what order would the liquids form layers from top to bottom ifthey were carefully placed in a container? a) C, B, A, D;
b) D, A, B, C;
c) A, B, C, D;
d) D, C B, A;
e) C, D, B, A
67) Suppose that a sample of a single unknown substance is contained in a metal box with a small hole in the lid. If one can smell an unusual odor just above the hole, one can be sure that the sample is a) a liquid; b) a gas; c) either a solid d) or a liquid, but not a gas; e) either a gas or a substance that readily gives off a gas.
68) Sulfur is a poor conductor of heat and electricity. Therefore, sulfur is probably
a) a solid;
b) a nonmetal;
c) inert;
d) malleable.
69) Volume is measured in a) liters; b) pounds; c) ounces; d) kilograms; e) none of these.
70) A rectangular solid with dimensions of 6.0 cm x 5.0 cm x 3.0 cm has a mass of 135 grams.
What is its density in g/cm3 ?
a) 0.67 b) 1.5 c) 90 d) 135 e) 12,150
71) Which of the following is not a characteristic property of metals?
a) high thermal and electrical conductivity
b) low melting point and boiling
c) point
d) ductility
e) malleability
f) metallic luster 72) The force between two bodies having identical electrical charges
a) is a force of repulsion.
b) is a force of repulsion if the charges are negative.
c) increases as the bodies are moved farther apart.
d) is independent of the distance between them.
e) is directly proportional to the distance between them.
73) When heating a test tube of liquid, which reason is the most important for movingthe test tube back and forth through the flame? a) mix the liquid b) prevent the liquid from burning c) prevent the test tube from cracking d) lessen evaporation of the liquid e) prevent local formations of vapor and ejection of the liquid
74) Solve for x: 227.4 = _x__
381.1 47.8
a) 0.04
b) 28.5
c) 80.1
d) 1,813.0
e) none of these
75) Solve for x: 99.8 / 203.1 = x / 75.7
a) 0.26
b) 37.2
c) 154.1
d) 267.8
e) none of these
76) Which set of metric prefixes have a conversion number of 10 between them?
a) 1) micro-kilo
b) kilo-centi
c) milli-deci
d) micro-centi
e) centi-deci
77) Find the correct arrangement of metric prefixes in order of decreasing value. a) kilo, deci, centi, micro b) milli, deci, centi, kilo c) micro, centi, deci, kilo d) kilo, micro, deci, milli.
78) Two prefixes used for units which are different by a factor of 100 are a) deci-milli; b) centi -- micro; c) kilo-- milli; d) micro-- kilo.
79) Use scientific notation to change 610 dekagrams to megagrams.
a) 6.1 x l0-5
Mg
b) 6.1 x l0-4
Mg
c) 6.l x l0-3
Mg
d) 6.1 x l07 Mg
80) How many milliliters are there in 73 deciliters? a) 0.0073
b) 0.73
c) 7,300
d) 73,000
e) none of these
81) Use scientific notation to convert 210 megagrams to centigrams. a) 2.1 x l0
-6 cg.
b) 2.1 x 10-2
cg.
c) 2.1 x l06
cg.
d) 2.1 x l0l0
cg.
82) How many hectometers are there in 480 centimeters? a) 0.048 hm b) 0.48 hm c) 4800 hm d) 480,000 hm e) none of these
83) The number of millimeters in 0.620 centimeters is
a) 62.0; b) 0.062; c) 6.20; d) 620; e) none of these.
84) Use scientific notation to convert 0.0081 micrometers to hectometers.
a) 8.1 x 10-13
hm
b) 8.1 x 10-11
hm
c) 8.1 x l0-7
hm
d) 8.1 x l05 hm
85) The number of kilometers in 5,280 decimeters is
a) 5.28 x 107;
b) 528;
c) 5.28;
d) 5.28 x 10-1
.
86) Convert 0.0105 micrometers to kilometers.
a) 1.05 x 107
km
b) 1.05 x 105
km
c) 1.05 x 104 km
d) 1.05 x 10-11
km
87) The number of centigrams in 0.25 kilogram is
a) 2.5 x 10-5
;
b) 2.5 x 10-2
;
c) 2.5 x 104;
d) 2.5 x 106;
e) none of these.
88) How many deciliters are there in 348 megaliters? a) 3.48 x 10
2dl
b) 3.48 x 106
dl
c) 3.48 x 109 dl
d) 3.48 x 10-5
dl
89) The correct arrangement of prefixes in order of increasing value is
a) milli, centi, kilo, deci; b) micro, milli, centi, kilo; c) centi, milli, kilo, deci; d) kilo, milli, centi, micro.
90) Change l,500,000 microliters to deciliters.
a) 0.0015 dl b) 15 dl c) 15,000 dl d) 150,000,000 dl
91) How many decigrams are there in 98.2 centigrams? a) 982.0 dg
b) 0.0982 dg
c) 0.982 dg
d) 9.82 dg
92) Convert 320 hectometers to megameters.
a) 0.032 Mm
b) 3.2 Mm
c) 32,000 Mm
d) 3,200,000 Mm
93) Convert 300 dekaliters to centiliters. a) 0.3 cl b) 3,000 cl c) 300,000 cl d) 3,000,000 cl e) none of these
94) 168. Convert 0.075 megagrams to decigrams.
a) 0.000,007,5 dg
b) 0.000,75 dg
c) 750 dg
d) 50,000 dg
95) What conversion factor would you use to convert milligrams to grams?
a) 1000 mg/1 g b) 1 mg
2/10 g
2
c) 1 g/1000 mg d) 1 g = 1000 mg
96) Use scientific notation to convert 5,800 deciliters to megaliters. a) 5.8 x l0
-4 Ml
b) 5.8 x l0-2
Ml
c) 5.8 x l08Ml
d) 5.8 x 1010
Ml
97) The correct arrangement of prefixes in order of increasing value is
a) kilo, deci, micro, milli;
b) micro, deci, centi, kilo; c) kilo, deci, centi, micro; d) milli, deci, kilo, centi; e) none of these.
98) What is the correct arrangement for metric prefixes in order increasing value?
a) micro, centi, kilo, deci b) centi, milli, kilo, micro c) milli, centi, deci, kilo d) kilo, milli, centi, micro
99) The prefix used in the metric system to indicate 0.01 is
a) kilo; b) deci; c) hecto; d) milli; e) centi.
100) Two prefixes that have a conversion number of 10 between them are
a) deci-milli;
b) enti-micro;
c) milli-centi;
d) kilo-milli.
e) none of these.
101) Calculate the number of megagrams in 27.6 hectograms. a) 2.76 x 10
-3 Mg
b) 2.76 x 104
Mg c) 2.76 x 10
5 Mg
d) 2.76 x 106 Mg
102) Two prefixes that have a conversion number of 10,000 between them are a) deci-milli;
b) centi-kilo;
c) milli-centi;
d) deci-kilo.
103) The prefix used in the metric system to indicate 0.00l is
a) kilo;
b) deci;
c) deca;
d) hecto;
e) none of these.
104) Use scientific notation to change 392,000,000 micrometers to millimeters.
a) 3.92 x 102
mm b) 3.92 x 105 mm c) 3.92 x 106 mm d) 3.92 x 10
11
105) The number of centiliters in 0.0576 kiloliters is
a) 5760;
b) 576.0;
c) 0.000, 576;
d) 57600;
e) some other value.
106) Change 0.000,093 dekameters to micrometers.
a) 0.0093 microm.
b) 0.93 microm.
c) 9.3 microm.
d) 930 microm.
107) A nickel has a mass of about five a) grams; b) milligrams; c) millimeters; d) milliliters; e) dekagrams.
108) What is the correct arrangement for metric prefixes in order of decreasing value?
a) kilo, deci, micro, milli b) micro, deci, centi, kilo c) deci, centi, micro, milli d) eci, centi, milli, micro
109) To measure the distance between cities, which would be the best unit to use?
a) kilometer
b) meter
c) centimeter
d) decimeter
e) megaliter 110) Which one of the following would best be used to measure the mass of an automobile?
a) megameter
b) gram
c) cubic meter
d) kilogram
e) liter
111) Two units of measurement that are almost equal are the
a) iter and the quart;
b) pound and the gram;
c) ton and the kilogram;
d) meter and the foot.
112) A chemical change always results characteristically in a change of
a) state; b) form; c) identity; d) size; e) shape.
113) Which of the following is a chemical change?
a) evaporation of water b) distillation of water c) freezing of water d) electrolysis of water
114) Chemical changes always involve a) the absorption of energy; b) the liberation c) of energy; d) either the absorption or liberation of energy; e) changes of state.
115) One physical property of sugar is its
a) acidity; b) reactivity; c) flammability; d) plasma qualities; e) solubility.
116) The majority of chemical changes are
a) autothermic; b) endothermic; c) isothermic; d) nonthermic; e) exothermic.
117) The statement which describes a physical property of the element oxygen is
a) oxygen supports the burning of paper; b) oxygen is needed for the rusting of iron; c) oxygen must be present for food to decay; d) oxygen has a density of 1.43 grams per liter; e) oxygen is a component of water.
118) In any chemical reaction energy is
a) always absorbed; b) always c) released; d) released as heat; e) usually not involved; f) either g) absorbed or released.
119) Which of the following is not a chemical change?
a) l) the dissolving of zinc by HCl b) the exploding of gasoline c) the corroding of a copper roof d) the boiling of water
120) One chemical property of a substance is a description of its a) odor; b) density; c) combustibility; d) solubility; e) none of these.
121) A new substance is formed as a result of a
a) physical change;
b) chemical
c) change;
d) physical property;
e) chemical property.
122) 1 Chemical changes differ from physical changes because in chemical changes
a) new substances are formed. b) a change in mass occurs. c) properties change. d) less energy change takes place.
123) When a substance changes and still retains its original properties, the change iscalled
a) chemical; b) exothermic; c) endothermic; d) physical.
124) Energy is involved in both physical and chemical changes. The energy in chemical
changes compared to physical changes is generally a) greater; b) the same; c) no different; d) greater in some but smaller in others.
125) Only a physical change takes place in
a) producing water by burning hydrogen in air. b) decomposing water into its elements by an electric current. c) hange water into ice by lowering its temperature. d) changing water into hydrogen and oxygen by heating it to a very high temperature.
126) An example of a physical change produced by the addition of energy is
a) condensation of steam; b) melting of ice; c) burning of oil; d) lighting e) of a match.
127) All of the following are chemical changes except the
a) souring of milk; b) neutralization of an acid; c) rusting of iron; d) tarnishing of silver; e) solution of sugar in water.
128) The properties of a substance that relate to its ability to form new substances are labeled
a) intensive; b) extensive; c) chemical; d) physical.
129) Which statement describes a physical property of elemental oxygen?
a) Oxygen has a density of 1.43 g./l.
b) Oxygen is needed for human metabolism.
c) Oxygen supports the burning of paper
d) Oxygen combines with iron to form rust.
130) The burning of hydrogen is a chemical change because
a) a gas changes to a liquid;
b) heat is produced;
c) a change in volume occurs;
d) a new substance with
e) different properties forms.
131) An example of a chemical change is the
a) condensation of steam; b) corrosions of metals; c) freezing of milk; d) dissolving of sugar; e) none of these.
132) An example of a physical change is
a) burning; b) decaying; c) melting; d) rusting; e) oxidation.
133) In a physical change of matter, a) a chemical change takes place; b) chemical properties change; c) molecules break into atoms; d) no new substances are formed; e) heat is gained.
134) .Which process is a chemical change?
a) the melting of ice b) the burning of a candle c) the magnetizing of steel d) the liquefaction of oxygen
135) Which of the following is a chemical property of matter?
a) color b) density c) flammability d) molecular mass e) vapor pressure
136) . An example of a chemical change is
a) burning magnesium; b) boiling water; c) tearing paper; d) melting lead.
137) All of the following are physical properties of active metals except the ability to
a) conduct heat;
b) free hydrogen from water;
c) be hammered into sheets;
d) take high luster when polished. 138) An example of a physical change is the
a) color change of leaves in the autumn; b) rust on a garden tool; c) process called photosynthesis; d) shredding a piece of paper.
139) . An example of a chemical reaction is the
a) explosion of fireworks; b) boiling of an egg; c) freezing of ice; d) drying of wet laundry.
140) According to makeup matter exists as a) elements, solids, metals, liquids b) elements, compounds, mixtures, solutions c) solids, liquids, gases, plasma.. d) solids, compounds, mixtures, liquids.
141) . The state of matter characterized by both a definite shape and a definite volume is a
a) fluid;
b) liquid;
c) solution;
d) gas;
e) none of these. 142) The state of matter which has no definite shape or volume is
a) gas; b) liquid; c) solid; d) water.
143) . Solids differ from liquids in that only samples of solids normally have definite
a) shapes;
b) volumes;
c) colors;
d) chemical compositions. 144) Matter that is characterized by neither a definite shape nor a definite volume is said to be
a) crystalline; b) liquid; c) solid; d) fluid; e) gaseous.
145) . According to the Kinetic Theory, the physical state in which particles are forced to
vibrate about fixed positions is a) solid; b) liquid; c) gaseous; d) fluid; e) aqueous.
146) Which is characteristic of the gaseous phase? a) Diffusion occurs slowly. b) Compression is difficult.
c) Particle arrangement in space is definite.
d) Particles have minimum translational energy.
e) Complete occupation of containing vessel occurs.
147) . The state of matter in which the molecules are practically independent of each other is
a) crystalline; b) solid; c) liquid; d) gaseous.
148) Which property is characteristic of a liquid?
a) It has a constant volume.
b) Intermolecular distances are large.
c) Diffusion is faster than in a gas.
d) Intermolecular forces are not very significant.
e) Expansion is appreciable as its temperature changes. 149) . Any sample of a compound
a) can consist of one element; b) is homogeneous; c) can have a varied chemical composition; d) can be decomposed by physical change.
150) A material that is made up of more than one kind of atom
a) can not be a compound; b) is an element; c) may be a mixture; d) must be a hydrate; e) none of these.
151) Which is characteristic of a compound?
a) It can consist of a single element. b) It is homogeneous. c) Its chemical composition can be varied. d) It can be decomposed by a physical change.
152) When a sample of a pure white substance is heated in a test tube, it gives off a reddish-brown colored gas and leaves a brown residue in the test tube. On the basis of this information it is most reasonable to conclude that the powder substance is a) a compound; b) an element; c) either an element or a compound; d) a solution.
153) The elements in a(n) ______________ are always in the same ratio.
a) compound
b) solution
c) alloy
d) mixture
e) none of these 154) Pure substances made of more than one element are call
a) compounds; b) mixtures; c) alloys; d) solutions.
155) Two pure substances A and B react to form a new pure substance C. From this we may conclude that a) A and B are both elements; b) C is a compound, A and B c) may or may not be elements; d) C is an element, A and B are compounds; e) A, B and C are all compounds.
156) An example of an element is
a) air; b) milk; c) mercury; d) salt; e) none of these.
157) When elements combine chemically, they always form
a) new elements; b) atoms; c) gases; d) mixtures; e) none of these.
158) Sugar is heated strongly in a test tube until it is completely changed into a charred black mass and drops of water. This experiment indicates that sugar is a) an element; b) a compound; c) heterogeneous; d) a solution; e) a crystal.
159) A substance that can be broken up into simpler substances by ordinary chemical methods
is a) an element; b) a compound; c) a mixture; d) a salt.
160) A substance which cannot be further decomposed by ordinary chemical means is
a) water;
b) air;
c) sugar;
d) carbon;
e) steel. 161) A substance composed of two or more elements chemically united is called
a) a reactant; b) a compound; c) an isotope; d) a mixture.