Six Weeks Review (7th)

Elements & Compounds

100

Give me an example of an element.

Ex: hydrogen, oxygen, carbon, etc.

(anything on the PT)

200

Give me an example of a compound.

Ex: H2O (Water), NaCl (salt), etc.

300

Name an easy way to tell the difference between an element and a compound.

Elements: found on the PT

Compounds: have more than one capital letter

400

Give me the definition of an element and a compound.

Element: Pure substance made of one type of atom

Compound: substance made of two or more atoms/ elements. (Opt: Chemically combined)

500

Which of the following do NOT describe an element:

1. A mixture of different chemicals 

2. Represented by a symbol that contains one uppercase letter 

3. Represented by a symbol that can contain a second uppercase letter 

4. Represented by a symbol that can contain a lower case letter 

5. A pure substance 

6. Can be identified using the periodic table 

1 and 3

P & C Changes

100

What is a physical change?

alters the form or appearance of matter

200

What is a chemical change?

new substances are formed

300

Give me two examples of both a physical and chemical change.

Physical ex: ice melting, cutting paper, chopping wood, etc.

Chemical ex: burning paper, baking a cake, metal rusting

400

Which of these are examples of physical changes? 

-burning wood

-breaking an egg

-cooking an egg

-freezing a popsicle

-rusting iron

breaking an egg and freezing a popsicle

500

List two evidences of both a physical and chemical change.

Physical: change in shape, size, state of matter

Chemical:

 -change in color, odor, temperature

- light, sound, precipitate produced

-formation of gas (bubbles)

Aqueous Solutions

100

What is an aqueous solution?

A solution where the solvent is water

200

Explain what the following are:

solution

solvent

solute

solution: a homogeneous mixture

solvent: substance that dissolves the solute

solute: substance that dissolves in water

300

Label the solvent, solute and solution for the following:

Lemon juice and sugar mixed with water result in lemonade. 

solvent: water

solute: lemon juice and sugar

solution: lemonade

400

Give me the definition of concentration and dilution.

Concentration: measurement of the amount of solute that is dissolved in a solvent. 

Dilution: a reduction in the concentration of a solute by adding more solvent to a solution.

500

Explain how you could make a solution less concentrated.

By adding more solvent/ water

Factors of Dissolution

100

What is the rate of dissolution?

how quickly a solute dissolves in a solvent

200

What is solubility?

The ability of a substance to dissolve in a solvent and form a solution

300

What are the 3 factors that affect the rate of dissolution? 

temperature

agitation

surface area

400

How can you slow down the rate of dissolution?

-use cold water

-not stir

-use big pieces of solute

500

How do the following factors affect the rate of dissolution:

-temperature

-surface area

-agitation

temp: causes the solute particles to move faster

agitation: moves the solvent particles around to collide with the solute

surface area: more surface area is exposed to the solvent

Counting Atoms

100

What does the coefficient tell us?

The number of molecules

200

What does the subscript tell us?

The number of atoms

300

How many hydrogen atoms are in the following:

5NH₄C₂H₃O₂

32 atoms

400

How many total atoms are in the following:

2C₉H₈O₄

42 total atoms

500

Tell me how many atoms there are of each element. 

4(NH₄)₂SO₄

Nitrogen: 8

Hydrogen: 32

Sulfur: 4

Oxygen: 16