WorksheetsCounting Atoms in Chemical Equations
Total questions: 20
Worksheet time: 10mins
Name
Class
Date
1.
How many Hydrogen atoms are in 4H2O?
a)
6
b)
8
c)
2
d)
4
2.
How many Oxygen atoms are in H2O?
a)
1
b)
2
c)
0
d)
4
3.
How many Magnesium atoms are in 10MgCl2?
a)
10
b)
5
c)
20
d)
12
4.
How many TOTAL atoms are there in:
H2SO4
H2SO4
a)
6
b)
5
c)
7
d)
3
5.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
6.
How many Sodium atoms are in 6NaCl?
a)
1
b)
12
c)
6
7.
How many atoms of Hydrogen are in this molecule?
a)
1
b)
2
c)
3
d)
4
8.
Element or Compound?
C2H8O
C2H8O
a)
Element
b)
Letters
c)
Numbers
d)
Compound
9.
A subscript is the small number to the lower left of a(n) ________ that tells the number of _______ of that element.
a)
element symbol; atoms
b)
atom; element symbol
c)
subscript; protons
d)
compound; elements
10.
Which is the correct formula for:
three hydrogen atoms (H)
one sulfur atom (S)
four oxygen atoms (O)
three hydrogen atoms (H)
one sulfur atom (S)
four oxygen atoms (O)
a)
H3SO4
b)
HSO4
c)
H4S3O
d)
H2O
11.
How many elements are in the compound C2H8O ?
a)
2
b)
1
c)
3
d)
0
12.
How many TOTAL atoms are in the compound?
C2H8O
C2H8O
a)
11
b)
2
c)
8
d)
1
13.
How many TOTAL atoms are in this compound?
H2C3O4N5
H2C3O4N5
a)
5
b)
14
c)
15
d)
19
14.
Element or Compound?
O2
O2
a)
Element
b)
Compound
15.
How many atoms are Carbon are in the compound C2H8O ?
a)
8
b)
2
c)
1
d)
11
16.
How many Nitrogen atoms are in 2AlN?
a)
4
b)
5
c)
1
d)
2
17.
How many atoms of Oxygen are in this molecule?
a)
1
b)
2
c)
3
d)
4
18.
Which of these is a molecule only, not a compound?
a)
H2Cr
b)
Cr3
c)
OH
d)
PNi
19.
What is a coefficient?
a)
The small number on the right of the chemical symbol
b)
The small number on the left of a chemical symbol
c)
A number that comes before a molecule and identifies how many molecules there are
d)
A number that comes after a molecule and identifies how many molecules there are
20.
A pure substance that cannot be broken down into simpler substances.
a)
element
b)
compound
c)
molecule
d)
carbon dioxide
100 %
