1. A group of students conducted an investigation in which they

added 4 different solid substances to separate beakers of water.

They stirred the mixtures for one minute and recorded

observation in the table below.

Which substance most likely caused a chemical reaction when

mixed with water?

A. Substance 1

B. Substance 2

C. Substance 3

D. Substance 4

7th Grade Science Unit 1 Pre-Test

2. A serving of fruit salad is shown below. There are various

shapes and colors.

What type of mixture is shown and why?

A. A homogeneous mixture, because the parts of the mixture can be

easily seen and separated. B. A homogeneous mixture, because the parts of the mixture are mixed

so well one part can not be differentiated from another and they are not easily separated.

C. A heterogeneous mixture, because the parts of the mixture can be easily seen and separated.

D. A heterogeneous mixture, because the parts of the mixture are mixed so well one part can not be differentiated from another and they are

not easily separated.

3. Which of the following is an example of a mixture rather than a

pure substance?

A. Distilled water B. hydrogen

C. Air in Earth’s atmosphere D. Gold

4. The table below shows the number of each kind of atom that

makes up one molecule of the compounds citric acid (vitamin C)

and glucose (a form of sugar).

Compound Number of Atoms per Molecule

Carbon Hydrogen Oxygen

citric Acid

6

8

7

glucose

6

12

6

Which of the following is the same for both compounds?

A. The mass of each molecule

B. The length of each molecule C. The types of atoms in each molecule

D. The number of atoms in each molecule

7th Grade Science Unit 1 Pre-Test

5. Table salt is a compound that is made up of Sodium and

Chlorine atoms that form a crystal. The chemical name of table

salt is sodium chloride and its chemical formula is NaCl. Which

of the following figures shows a model of table salt?

A. C.

B. D.

6. A student observes sugar as it is heated and burns. The student

concludes that a chemical reaction has occurred. Which of the

following observations about burning sugar provides evidence

of a chemical reaction?

A. Heat is added to the sugar crystals.

B. Gas is produced and the sugar turns black.

C. The sugar melts and becomes a liquid.

D. None of the above

7.

Density is mass divided by volume. The ring has a mass of 16

grams. Its density is

A. 18 g/cm3.

B. 16 g/cm3. C. 4 g/cm3.

D. O.4 g/cm3.

7th Grade Science Unit 1 Pre-Test

8. Which of the following is a characteristic of all chemical

changes?

A. A different state of matter is produced.

B. Some mass is converted to energy.

C. Some form of light is given off.

D. A new material is formed.

9. In a class experiment 5 grams of salt is dissolved in 100 ml of

distilled water to form a salt water solution. The solution is

heated and the water boiled away. How much salt should be

left in the container?

How much salt should be left in the container?

A. 2.5 grams

B. 105 grams

C. 500 grams

D. 5 grams

10. Students fill a graduated cylinder with three liquids, 1, 2, and 3,

and then add three solid objects, A, B, and C. Use the diagram

to determine which one of the following statements is correct.

A. Object B is heavier than Object C.

B. Object B and C have the same density.

C. Object B is less dense than Liquid 3.

D. Object B is less dense than Liquid 1.

7th Grade Science Unit 1 Pre-Test

Read the following selection and answer the question. Use the investigative

evidence to support your claims.

In a Science Lab, groups of students recorded the observations

shown in the Data Table 1 below. Classify each group’s observation

as a physical or chemical change. If a phase change such as boiling

occurred, name the phase change. Complete Table 2 showing your

claim, evidence, and reasoning.

Data Table 1: Groups 1-4 Observations

Group Observation

1 Solid dry ice changed into a gas.

2 A red liquid changed to a red gas.

3 A soft silver metal changed to a silver liquid.

4 A reddish metal formed a thin black layer that could be

scraped off to show the reddish metal beneath.

Data Table 2: Claims, Evidence, Reasoning

Record your answer here.

Question: Is it a physical or chemical change? If it is a phase change like boiling, write phase change and the name of the phase change.

Group Observation Claim

Evidence

Describe the

evidence that

supports your claim.

Reasoning

Describe your reasoning of why the evidence supports your

claim.

1 Solid dry ice

changed into a

gas.

2 A red liquid

changed to a red

gas.

3 A soft silver

metal changed to

a silver liquid.

4 A reddish metal

formed a thin

black layer that

could be scraped

off to show the

reddish metal

beneath.

7th Grade Science Unit 1 Pre-Test