B
NAME _______________________________
For each problem, you must follow these steps:
2H2O
subscript
► Recognize and record individual elements. coefficient
► Recognize the subscripts as the number of atoms for an element.
► Recognize the coefficient as the number of molecules of that substance.
► Calculate the total number of atoms making up the chemical formula.
Examples:
a) NaCO3
b)
5ZnSO4
1)
NH4HCO3
8)
3BaI2
2)
CeCl3
9)
4Si2H6
3)
2Gd2O3
10) ErAg
4)
5CH3COOH
11) H2S
5)
LiFePO4
12) 3HgSO4
6)
RbNO3
13) 7H2CO
7)
3C8H10N4O2
14) ZnCrO4
Na
1
C
1
O
3
Answer: 5 total atoms
Copyright © 2016 Travis Terry
Zn
5×1=5
C
5×1=5
O
5 × 4 = 20
Answer: 30 total atoms
B
NAME _______________________________
For each problem, you must follow these steps:
2H2O
subscript
► Recognize and record individual elements. coefficient
► Recognize the subscripts as the number of atoms for an element.
► Recognize the coefficient as the number of molecules of that substance.
► Calculate the total number of atoms making up the chemical formula.
Examples:
a) NaCO3
b)
5ZnSO4
1)
8)
3BaI2
Na
1
C
1
O
3
Answer: 5 total atoms
NH4HCO3
► 10 atoms
2)
CeCl3
► 9 atoms
9)
► 4 atoms
3)
2Gd2O3
5CH3COOH
10) ErAg
► 2 atoms
11) H2S
► 40 atoms
5)
LiFePO4
► 3 atoms
12) 3HgSO4
► 7 atoms
6)
RbNO3
► 18 atoms
13) 7H2CO
► 5 atoms
7)
3C8H10N4O2
4Si2H6
► 32 atoms
► 10 atoms
4)
Zn
5×1=5
C
5×1=5
O
5 × 4 = 20
Answer: 30 total atoms
► 28 atoms
14) ZnCrO4
► 72 atoms
► 6 atoms
Copyright © 2016 Travis Terry