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WorksheetsGrade 7 L-2: Property Changes in Chemical Reactions 2025
Total questions: 72
Worksheet time: 42mins
Equal amounts of something
balanced
coefficient
equation
product
A particular smell
matter
odor
substance
mass
Matter changes into other substances with different chemical and physical properties.
proof
equation
chemical change
odor
The total mass before a chemical reaction is the same as the total mass after the chemical reaction
reaction
substance
product
The law of conservation of mass
Atoms of one or more new substances rearrange to form one or more new substances.
mass
chemical
chemical reaction
formula
The starting substances in a chemical reaction.
equation
reactants
mass
reaction
The substances produced by the chemical reaction.
Products
law
reaction
substances
A number placed in front of an element symbol or chemical formula in an equation.
odor
property
coefficient
product
Which is a statement of the law of conservation of mass?
Mass can be created or destroyed in a reaction.
The total mass before a chemical reaction is the same as the total mass after the reaction.
Every reaction creates an equal amount of mass related to the amount of energy required for the reaction.
The total amount of mass is equal to the volume of both chemicals in the reaction.
When a substance undergoes a chemical change, its identity does not change. _______________
True
False
Which of the following is an example of a chemical change?
bending a pop can
evaporating of milk
melting wax
burning paper
An example of a chemical change is ____.
a magnet sticking to the refrigerator
dew disappearing from the grass
mashing potatoes
frying a hamburger
Which of the following is an example of a chemical reaction?
lighting a match
dissolving salt into water
freezing water
breaking a glass
A change in color is evidence of a _______________.
Physical change
Physical property
Chemical change
Chemical property
When a log burns in a fire, _____.
a physical change has occurred
mass is gained
mass is lost
new substances are formed
True or False: Mass is conserved in the following reaction.
True
False
Which of the substances in the reaction is a reactant?
Vinegar (HC2H2O2)
Sodium acetate (NaC2H3O2)
Water (H2O)
Carbon dioxide (CO2)
Which of the substances in the reaction is (are) a product(s)?
Baking Soda (NAHCO3)
Vinegar (HC2HCO3)
Sodium Acetate (NaC2H3O2)
Carbon Dioxide (CO2)
Which of the following are signs of a chemical change in a closed system?
Tick all that apply.
Change in mass
Change in colour
Release of energy
Formation of a new substance
Salt dissolving (mixing) in water is a chemical change
True
False
Which of the following is the correct way to write a chemical equation?
Product + product --> reactant + reactant
Reactant + reactant --> product + product
Product + reactant --> product + reactant
Reactant + product --> reactant + product
During a chemical reaction, mass is sometimes created and destroyed.
True
False
Which can change during a chemical reaction?
The total mass of the system
The identity of the substances
The atoms that make up the substances
Burning is ALWAYS a chemical reaction.
True
False
Which is a common example of chemical change?
Cutting paper
Sticking a magnet to metal
Turning on a lightswitch
Cooking a burger
A product is
The end result of a chemical property.
The starting substances of a chemical reaction.
The substance(s) formed at the end of a chemical equation
Which is not an example of chemical reaction
Why does a mass remains the same in a chemical reaction?
Because of the rules of conservation
Because the atoms also remains the same
Because it does not become bigger
Because gravity is always the same.
Which is a statement of the law of conservation of mass?
Mass can be created or destroyed in a reaction.
The total mass before a chemical reaction is the same as the total mass after the reaction.
Every reaction creates an equal amount of mass related to the amount of energy required for the reaction.
The total amount of mass is equal to the volume of both chemicals in the reaction.
(OH)2
During the Fall, leaves changed on the trees. What sign of a chemical change is this?
Color change
Increase of light
The formation of a percipitate
Which observation is a sign of a chemical change?
bubbles escaping from the combination of baking soda and vinegar
iron filings sticking to a magnet
lights flashing from fireworks
water turning to ice in a freezer
If an ice pack vial was popped and it started getting icy cold, what kind of reaction occurred in the ice pack?
It is a physical change as evidenced by a drop in temperature.
It is a chemical change because two different chemicals are mixed together.
It is a chemical change because heat energy is absorbed and the pack gets colder.
It is a physical change because the substance in the vial dissolved in the pack's liquid.
What type of reaction are fireworks?
It is a change of state, solid to gas, due to the addition of energy.
It was a physical reaction since the fuse was lit and heat was produced.
The color changes and the release of energy indicate a chemical reaction.
It is an endothermic reaction because energy was added; therefore it is a chemical reaction.
Which is an example of a chemical change?
the odor of sour milk
dissolving sugar into water
a button sinking in a cup of water
ice melting
The amount of matter in an object is its
mass.
inertia.
weight.
volume.
A change that results in a new substance being formed.
physical
chemical
compound
Baking a cake is an example of what property of matter?
physical
chemical
mass
Burning paper is an example of what type of change?
chemical
physical
energy
What is volume?
The amount of space an object takes up
Matter
Mass
The measure of energy of motion of the particles of matter which feels as hot or cold something is.
Boiling Water
Ice
Temperature
Vocab: The basic unit from which all matter is made.
molecule
atom
element
compound
Vocab: Substances that are made up of only one type of atom.
molecule
atom
element
compound
Vocab: A substance made of two or more elements that are chemically combined in a set ratio.
molecule
atom
element
compound
Select all that apply: the states or phases of matter are:
gases
molecules
liquids
atoms
solids
Anything that has mass or takes up space.
mass
matter
volume
state
The amount of space something takes up.
volume
mass
weight
state
if the containers are A B C:
which of the containers contains a solid?
A
B
C
