classification of matter - kids in prison program...6 solid amorphous solid crystalline solid...

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Classification of MatterChapter 3

Hein and Arena

Eugene Passer

Chemistry Department

Bronx Community College

© John Wiley and Sons, Inc

Eugene Passer

Chemistry Department

Bronx Community College

© John Wiley and Sons, Inc

Version 1.0

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Matter Defined

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Matter is anything that has mass

and occupies space. It can be pure

or a mixture.

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Physical States of

Matter

(Solid, Liquid and Gas)

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Definite shape

Definite volume

Particles are close

Very slight compressibility

SOLIDS

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Solid

Amorphous Solid Crystalline Solid

Particles lack a regular

internal arrangement

Particles exist in regular, repeating

three-dimensional geometric patterns.

Glass, plastics, gels Diamond, metals, salts

A solid can be either crystalline or amorphous

depending on the internal arrangement of the particles

that constitute the solid.

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Indefinite shape

Definite volume

Particles are close – not as close as in solids

Slight compressibility – greater than solids

LIQUIDS

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GASES

No fixed shape

No fixed volume

Particles are far apart

Very compressible

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ATTRACTIVE FORCES

Solid particles have strong attractive

forces between them (i.e. “closest” proximity).

Liquid particles have intermediate attractive

forces between them (i.e. “medium” proximity).

Gas particles have extremely weak attractive

forces between them (i.e. “least” proximity).

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Substances and

Mixtures

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Substance

A particular kind of matter that has a fixed

composition and distinct properties.

Examples

ammonia, water, and oxygen.

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Homogeneous Matter

Matter that is uniform in appearance

and properties throughout.

Examples

Ice (without bubbles) , milk, pure gold

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Heterogeneous Matter

Matter that is not uniform in appearance

or properties throughout.

Examples

ice and water, wood

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Homogeneous

Heterogeneous

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The Three Phases of Matter

Solid phaseLiquid phaseGas phase

Examples

In an ice water mixture, ice is the solid

phase and water is the liquid phase.

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Mixture

Matter containing 1, 2 or more substances that can be homogeneous or heterogeneous.

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Homogeneous Mixture (Solutions)

A homogeneous mixture consists of 2 or

more substances, and has one phase (i.e.

solid, liquid or gas).

Example

Sugar completely dissolved in water.

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Example

Sand added to water.

Heterogeneous Mixture

A heterogeneous mixture consists of 2 or

more phases of one or more substances.

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Heterogeneous Mixture

of One Substance

A pure substance can exist as different

phases in a heterogeneous system.

Example

Ice floating in water.

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Elements

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An element is a fundamental substance

that cannot be broken down into simpler

substances by simple chemical or

physical means.

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Each element has a number; the atomic number.

Hydrogen has an atomic number of 1.

Calcium has an atomic number of 20.

Iron has an atomic number 26.

The atomic number defines what the element.

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ATOM

• The atom is the smallest particle of an

element that exhibits the characteristic

properties of the element.

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Symbols of the

Elements

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• A symbol of an element stands for …

– the element itself

– one atom of the element

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Ne neon

Rules governing symbols of the elements

are:

1. Symbols have either one or two letters.

2. If one letter is used, it is

capitalized.

3. If two letters are used, only

the first is capitalized.

H hydrogenC carbon

Ba barium

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Today’s Assignment!

• Please learn the names and chemical

symbols of elements 1 through 36 and

82. Thanks!

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Metals, Nonmetals

and Metalloids

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Metals

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• Have relatively high melting points

• Have high densities (g/mL).

• Excellent conductors of heat and electricity

• At room temperature metals are solids except

mercury.

Physical Properties of metals

• High luster

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• Many metals readily combine with nonmetalsto form compounds called ionic compounds.

– They can combine with sulfur.

• Metals have little tendency to combine with

each other to form compounds.

chlorine.

Chemical Properties of Metals

oxygen.

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Nonmetals

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• Have relatively low melting points

• Have low densities.

• Poor conductors of heat and electricity

• At room temperature carbon, phosphorous

and sulfur are solids.

Physical Properties of Nonmetals

• Lack luster

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• Many nonmetals readily combine with othernonmetals to form compounds calledmolecular compounds.

Chemical Properties of Nonmetals

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Metalloids

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Metalloids have properties that

are intermediate between metals

and nonmetals

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The Metalloids

1. boron

2. silicon

3. germanium

4. arsenic

5. antimony

6. tellurium

7. polonium

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Metals are found to the left of the metalloidsNonmetals are found to the right of the metalloids.

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Compounds

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A compound is a distinct substance that

contains two or more atoms combined in

a definite proportion.

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• Compounds can be decomposed into

simpler substances.

• Elements cannot be easily decomposed

into simpler substances.

• Atoms of a compound are always

present in whole numbers.

CH4, C2H4, AlCl3, etc.

The subscripts in the formula represents the

number of atoms of each element present.

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Ba3(PO4)2

indicates three

Ba atoms

3-

4phosphate (PO )

indicates two

groups

indicates

the element

barium

indicates the phosphate group

composed of one phosphorous

atom and four oxygen atoms

Channel Setting Instructions for ResponseCard RF

1. Press and release the "GO" or "CH" button.

2. While the light is flashing red and green, enter the 2 digit channel code (i.e. channel 1 = 01, channel 21 = 21).

Channel is 02

3. After the second digit is entered, Press and release the "GO" or "CH" button. The light should flash green to confirm.

4. Press and release the "1/A" button. The light should flash amber to confirm.

How many atoms are present in Li2SO4?

1 2 3 4

28%

3%

68%

2%

1. 6

2. 4

3. 7

4. 3

How many atoms are present in Li2SO4?

There are 2 lithium (Li) atoms, 1 sulfur (S) atom and 4 oxygen (O) atoms for a total of seven atoms.

The subscripts represent the number of atoms of each element present in the formula.

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There are two types of compounds:

molecular and ionic.

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Molecules

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A molecule is an individual unit of a

compound formed by the combination

(i.e. bonding) of two or more atoms,

typically nonmetals atoms.

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• A water molecule consists of two

hydrogen atoms and one oxygen atom.

3.5

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Ionic Compounds

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Ionic compounds are held together by

electrostatic attractive forces between

positively and negatively charged ions.

Ionic compounds result when the ions of a

metal and a nonmetal combine

An ion is a positively or negatively charged

atom (monatomic ion) or group of

atoms (polyatomic ion).

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A positively charged ion is called a

Cation; typically a metal.

Na Na+ + e-

3.5

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A negatively charged ion is called an

Anion; typically a nonmetal.

Cl + e- Cl-

3.5

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Positively charged sodium ions and

negatively charged chloride ions.

Sodium Chloride

3.5

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The crystalline structure of sodium chloride.

Sodium Chloride

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Ionic Compound Formulas

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Sodium chloride and other ionic

compounds consist of large aggregates

of cations and anions.

The formulas of ionic compounds are

expressed as the smallest whole number

ratio that exists between the cations and

the anions.

NaClCaCl2

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• The formula NaCl does not mean that

a molecule of NaCl exists; it does not!

• The formula NaCl means that the

ratio of sodium to chlorine in a

sodium chloride crystal is 1:1.

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The ratio of Na+ to Cl- is 1:1

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3.4

Compounds can be classified as molecular or

ionic.

Ionic compounds – ionic bonds.

Molecular compounds - covalent bonds.

Nonmetal - Nonmetal Metal - Nonmetal

Ionic Bonds: a complete transfer of e- from metal to nonmetal.

Covalent Bonds: a sharing of e- between the nonmetal and

nonmetal.

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Elements That Exist as

Diatomic Molecules

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A diatomic molecule contains exactly two

atoms of the same element.

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Chemical Formulas

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Rules for Writing Chemical Formulas

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NaCl

indicates

the element sodium

(one atom); the metal

appears 1st in formula.

indicates

the element chlorine

(one atom); the non-

metal appears 2nd in

Formula.

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indicates

3 H atoms

indicates

the element

phosphorous (P)

indicates

the element

hydrogen (H)

indicates

the element

oxygen (O)H3PO4

indicates

4 O atoms

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When a formula contains two or more ofthe same polyatomic ion, parentheses areplaced around it, and the number of unitsof the group is indicated by a subscriptplaced to the right of the parentheses.

Phosphate ion: PO4-3

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Ba3(PO4)2

indicates three

Ba atoms

3-

4phosphate (PO )

indicates two

groups

indicates

the element

barium

indicates the phosphate group

composed of one phosphorous

atom and four oxygen atoms

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Formulas written as H2O, H2SO4,

Ca(NO3)2 and C6H6 do not show the

spatial arrangements of the atoms.

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H2O

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