WorksheetsChemical Reactions
Total questions: 15
Worksheet time: 5mins
Name
Class
Date
1.
When a magnesium ribbon is burnt in air, the ash formed is
a)
Black
b)
White
c)
yellow
d)
Pink
2.
In a ___________change, a substance changes into a different substance.
a)
Physical
b)
Chemical
3.
Which of these is NOT a sign that a chemical change has occurred?
a)
A loss of transparency
b)
An unexpected color change
c)
A temperature change
d)
The formation of a precipitate
4.
In a chemical reaction, bonds are broken and new bonds are formed that create new substances. The bonds that are broken are called what?
a)
Reactants
b)
Products
c)
Atoms
d)
Catalysts
5.
The Law of Conservation of Mass states
a)
that matter exists in all states and reacts the same
b)
that matter can only be changed into new substances by introducing a catalyst
c)
that matter exists in the same state throughout any chemical change
d)
that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants
6.
How many Al atoms are in this compound? 4Al2O3
a)
2
b)
8
c)
6
d)
4
7.
a copper penny turning greenish after a few years.
a)
Chemical Change
b)
Physical Change
8.
An gel ice pack getting cold after you put it in the freezer for an hour.
a)
Chemical Change
b)
Physical Change
9.
Which of the following IS a physical change?
a)
Getting a haircut
b)
Rusty metal
c)
sour milk
d)
A compound
10.
___________________ are the elements are compounds that leave (are formed in) a chemical
reaction.
reaction.
a)
Polymers
b)
Bonds
c)
Reactants
d)
Products
11.
Which is the name of the kind of solid substance formed in this figure?
a)
aqueous
b)
precipitate
c)
acid
d)
synthesis
12.
What is PROOF that a chemical change has occured?
a)
a new substance with different properties is created.
b)
you can put the reactants back together
c)
the substance changes state, solid to liquid or liquid to solid.
13.
What is the arrow in a chemical equation...
H2 + O --> H2O
H2 + O --> H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
14.
The substances at the beginning of a chemical equation are called the ____
a)
product
b)
yield
c)
chemical symbol
d)
reactants
15.
The equation below represents a chemical reaction that occurs in living cells. How many atoms are represented in the reactants of this equation?
a)
6
6
6
b)
12
12
12
c)
24
24
24
d)
36
36
36
100 %
