Quiz about Chemical Reactions Unit

Question 1

The smallest particle of an element; made of electrons, protons, and neutrons

Accepted Answer

Atoms

Answer

Elements

Answer

Molecules

Answer

Products

Question 2

The process by which one or more substances change to produce one or more different substances

Accepted Answer

Chemical Reaction

Answer

Chemical Process

Answer

Reactant

Question 3

The simplest unit of a chemical compound that can exist; formed when two or more atoms join together chemically

Accepted Answer

Molecule

Answer

Atom

Answer

Compound

Question 4

A substance produced during a chemical reaction

Accepted Answer

Product

Answer

Reactant

Answer

Properties

Question 5

Physical and chemical characteristics of matter used to describe or identify a substance

Accepted Answer

Properties

Answer

Chemical Reaction

Answer

Product

Question 6

A substance that takes part in and undergoes change during a reaction

Accepted Answer

Reactant

Answer

Product

Answer

Molecule

Question 7

A chemical reaction or process that absorbs heat from the surroundings

Accepted Answer

Endothermic

Answer

Exothermic

Question 8

A chemical reaction or process that releases heat.

Accepted Answer

Exothermic

Answer

Endothermic

Question 9

The Law of Conservation of Mass states

Accepted Answer

that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

Answer

that matter exists in all states and reacts the same

Answer

that matter can only be changed into new substances by introducing a catalyst

Answer

that matter exists in the same state throughout any chemical change

Question 10

How many Al atoms are in this compound? 4Al₂O₃

Accepted Answer

8

Answer

2

Answer

6

Answer

4

Question 11

How many F atoms are in this compound?
6MgF₂

Accepted Answer

12

Answer

2

Answer

6

Answer

8

Question 12

a copper penny turning greenish after a few years.

Accepted Answer

Chemical Change

Answer

Physical Change

Question 13

An gel ice pack getting cold after you put it in the freezer for an hour.

Accepted Answer

Physical Change

Answer

Chemical Change

Question 14

Which of the following IS a physical change?

Accepted Answer

Getting a haircut

Answer

Rusty metal

Answer

sour milk

Answer

A compound

Question 15

True or False
In a chemical reaction, no new atoms are created, and no atoms are destroyed.

Accepted Answer

true

Answer

false

Question 16

A chemical change is different than a physical change because in a chemical change

Accepted Answer

A new substance is formed and in a physical change no new substance is formed

Answer

Chemicals are used

Answer

Molecules do not physically touch

Answer

The change can be seen but in a physical change it cannot

Question 17

The left side of the equation below is called

Accepted Answer

Reactants

Answer

Products

Question 18

The right side of the equation below is called the

Accepted Answer

products

Answer

reactants

Question 19

Which statement is not a description of a chemical reaction?

Accepted Answer

A liquid is heated in the sun and half of it evaporates.

Answer

A solid is dropped into a beaker of liquid and a gas is released.

Answer

Two liquids are mixed in a beaker and a solid forms at the bottom of the beaker.

Answer

A solid is dropped into a beaker of liquid and an explosion occurs.

Question 20

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.

Accepted Answer

Coefficient

Answer

reactant

Answer

subscript

Answer

product

Question 21

Which of the following is NOT a sign of a chemical reaction?

Accepted Answer

Cutting into fourths

Answer

Color changes

Answer

Light is produced

Answer

Gas is formed

Question 22

In a chemical reaction

Accepted Answer

The atoms of the reactants unbond, rearrange, and then rebond to form the products

Answer

The atoms of the reactants always stay together to form the products

Answer

New atoms are formed which combine to make the products

Answer

Some atoms disappear while others multiply to form the products

Question 23

When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic?

Accepted Answer

a temperature increase

Answer

a change of color

Answer

a change of state

Answer

a temperature decrease

Question 24

What types of reactions absorb and release heat?

Accepted Answer

endothermic and exothermic

Answer

acidic and basic

Answer

endothermic and heat transfusion

Answer

covalent and ionic

Question 25

Which of the following is a chemical change?

Accepted Answer

gasoline burns in a car engine

Answer

water freezes to form ice

Answer

sugar dissolves in water

Answer

a piece of metal expands when it is heated

Question 26

In the reaction methane + oxygen turns into carbon dioxide + water, the methane and oxygen are called _______________.

Accepted Answer

reactants

Answer

products

Answer

neutrals

Answer

energizers

Question 27

A change in the shape of an object is an example of _________________.

Accepted Answer

a physical change

Answer

a chemical change

Answer

energy

Answer

an endothermic change

Question 28

What type of change occurs when a new substance is formed that has different properties from the original substances?

Accepted Answer

chemical change

Answer

nuclear change

Answer

physical change

Answer

mutation

Question 29

Which of the following represents a chemical change?

Accepted Answer

burning a piece of notebook paper in the presence of oxygen

Answer

cutting a piece of paper with scissors

Answer

cooling a mixture of air and kerosene vapor to obtain liquid kerosene

Answer

heating water over a flame to its boiling point

Question 30

Which of the following is an example of a chemical change?

Accepted Answer

rusting of a bicycle

Answer

painting a house

Answer

washing a dog

Answer

tearing up a newspaper

Question 31

Which of the following is a chemical change?

Accepted Answer

the rusting of iron

Answer

dissolving salt in water

Answer

melting an ice cube

Answer

bending a copper wire

Question 32

Which of the following is an example of a physical change?

Accepted Answer

mixing oil and vinegar

Answer

souring milk

Answer

mixing baking soda and vinegar

Answer

rusting metal

Question 33

Which is an example of a physical change?

Accepted Answer

using sand and water to build a sand castle on a beach

Answer

sodium and chlorine form salt

Answer

a copper ring turns white and green

Answer

a log burns in a fire

Question 34

Which of the following is an example of a physical change?

Accepted Answer

ice melting

Answer

wood burning

Answer

food digesting

Answer

iron rusting

Question 35

In any chemical reaction, the mass of the products is always:

Accepted Answer

the same as the mass of the reactants

Answer

slightly less than the mass of the reactants

Answer

much less than the mass of the reactants

Answer

greater than the mass of the reactants

Question 36

How do chemical reactions turn substances into new substances?

Accepted Answer

the atoms break apart and combine back together in new ways

Answer

with burning acid

Answer

the molecules mix together and create new substances

Answer

the ionic compounds mix in water to form solutions

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