WorksheetsScale 1-5 Chemical Reactions
Total questions: 18
Worksheet time: 9mins
A chemical change is when two or more substances combine to make a new substance.
True
False
An example of a chemical change is boiling a pot of water on the stove.
True
False
Another term to describe chemical change is ______________.
Chemical reaction
There is none
Change of a chemical
Chemical process
Chemical reactions happen when __________ hook together.
Protons
Atoms
Electrons
Elements
What is the total number of atoms?
NaOH
1
2
3
15
What is the total number of atoms?
(NH4)3PO4
29
20
3
15
What are the original substances called in a chemical equation?
Products
Reactants
atoms
molecules
What are the substances created during a chemical reaction called?
Products
Reactants
atoms
molecules
The law of conservation of matter states: Matter can never be _______ or ______ in a chemical reaction.
destroyed, stay the same
created, form molecules
destroyed, created
None of the above
Subscripts are found to the ______ of an element.
Left
Bottom Left
Right
Bottom Right
Coefficients do what to a formula?
Multiply all of the subscripts by the number of the coefficient.
Divide the total number of atoms by the number the coefficient is.
Replace the first subscript with the number of the coefficient.
Add the number of the coefficient to the total number of atoms.
The number of atoms before and after a reaction is...
different
the same
slightly less
slightly more
Physical or chemical change?
Toasting a piece of bread
Physical
Chemical
Physical or chemical change?
Frost forming on the grass in the morning
Physical
Chemical
Physical or chemical change?
Digesting a sandwich into nutrients for the body
Physical
Chemical
What is the MAIN evidence of the chemical change?
Fireworks bursting in the sky on the 4th of July
Color Change
Odor was given off
(smell)
Heat or light is created.
New matter is created
What is the evidence of the chemical change?
Eggs start to rot sitting in the fridge
Color Change
Odor was given off
(smell)
Heat or light is created.
New matter is created
What is the evidence of the chemical change?
Wood burning while roasting a golden brown marshmellow
Color Change
Odor was given off
(smell)
Heat or light is created.
New matter is created
