Font size
Worksheets123s of Chemistry Review
Total questions: 41
Worksheet time: 21mins
cutting down a tree is an example of a:
physical change
chemical change
photosynthesis is an example of a:
physical change
chemical change
making a sand castle is an example of:
physical change
chemical change
an apple turning brown is an example of:
physical change
chemical change
coloring is an example of:
physical change
chemical change
The substance that is made AFTER a chemical reaction has occurred is known as the __________________. It is found to the right of the yield sign (arrow).
product
reactant
mass
stuff
The ____________ tells us how many ATOMS are needed in the equation.
subscript
coefficient
product
mass
One molecule of hydrogen peroxide contains 2 HYDROGEN AND 2 OXYGEN atoms. The chemical formula for hydrogen peroxide is:
H2O
HO2
H O
H2O2
Water (H2O) is made up of the elements:
helium and carbon
hydrogen and oxygen
sodium and chlorine
hydrogen and chlorine
In a chemical symbol:
all the letters are capitalized
only the first letter of the symbol is capitalized
none of the letters are capitalized
scientists do not use letters in a chemical symbol
To determine if a substance is an element or a compound you could:
look to see if it is on the periodic table of elements
look to see if the formula has two capital letters
both answers A and B are correct
neither answers A or B are correct
Which of the following does not describe the LAW OF CONSERVATION OF MASS?
Mass can not be created but it can be destroyed by burning it.
Mass can not be created or destroyed, but it can change forms.
The law can be used to balance chemical equations. The number and type of atoms must be the same for both the reactants and the products.
The mass of the products equals the mass of the reactants.
The formula for ETHYLENE is C2H4.
Ethylene has:
4 atoms of carbon and 2 atoms of hydrogen
6 atoms of carbon and 2 atoms of hydrogen
2 atoms of carbon and 4 atoms of hydrogen
6 atoms of carbon and hydrogen
Atoms of ONLY ONE TYPE are called:
chemical bonds
elements
compounds
water
In a chemical formula like H2O, the number AFTER a symbol tells:
the number of protons
the number of electrons
the number of neutrons
the number of atoms needed
Carbon Dioxide (CO2) is made up of Carbon and
dioxide
oxygen
calcium
hydrogen
When you combine TWO or more DIFFERENT ELEMENTS you create a(n):
element
compound
atomic number
atom
All matter is made of:
atoms
nothing
gas
liquids
Making a paper airplane is an example of:
chemical change
physical change
Your bike rusting is an example of:
chemical change
physical change
Burning a log is an example of:
chemical change
physical change
Ice cream melting is an example of:
chemical change
physical change
Digesting food is an example of:
chemical change
physical change
The coefficient 3 in a chemical formula tells us to create ___________ of the compound.
3 atoms
3 molecules
3 elements
compounds
In the chemical formula, 2H2O2, you need:
2 hydrogens and 2 oxygens
4 hydrogens and 2 oxygens
4 hydrogens and 4 oxygens
2 hydrogens and 4 oxygens
An expression which tells the number and type of atoms in a molecule is called a:
atom
chemical formula
coefficient
chemistry teacher
The smallest particle of a compound held together by a chemical bond is a:
compound
molecule
coefficient
atom
The substance that is present at the start of a chemical reaction is called the __________. It is found in front of the arrow (yield).
reactant
product
coefficient
compound
The ____________ tells us how many MOLECULES are in the formula.
reactant
product
coefficients
subscript
In the formula, NH3 there are a total of __________ atoms used.
2
3
4
5
Which of the following are compounds:
Li2CO3
Co8
HeO2
O2
FeO2
Cl2 + 2NaBr ----> 2NaCl + Br2
What elements make up this equation?
Carbon, Nitrogen, Bromine
Carbon, Sodium, Bromine
Chlorine, Sodium, Bromine
Salt and Bromine
Cl2 + 2NaBr ----> 2NaCl + Br2
What is the total number of atoms on the reactants side of the equation?
4
3
5
6
Cl2 + 2NaBr ----> 2NaCl + Br2
What is the total number of atoms on the products side of this equation?
6
5
4
3
Cl2 + 2NaBr ----> 2NaCl + Br2
Was mass conserved during this chemical reaction? (Think about how you know.)
Yes
No
Which of the following is a chemical change?
Breaking a glass
Boiling water
Rusting of iron
Melting butter
What does the subscript in a chemical formula indicate?
The mass of the compound
The type of chemical bond
The number of molecules
The number of atoms of that element
Which of the following is an example of a compound?
Oxygen (O2)
Hydrogen (H2)
Water (H2O)
Gold (Au)
Which of the following is a physical change?
Rusting a nail
Baking a cake
Freezing water
Burning paper
What does a subscript in a chemical formula represent?
The number of atoms of an element
The number of molecules
The type of chemical bond
The mass of the compound
Which statement best describes a compound?
A substance formed when two or more elements are chemically combined
A mixture of different elements
A physical blend of substances
A substance made of only one type of atom
