Counting Atoms Worksheet
Directions for each problem:
1) Recognize and record individual elements
2) Recognize the subscripts as the number of atoms for an element
3) Recognize the coefficients as the number of atoms for all elements in the compound.
4) Total all atoms for an element.
Examples:
a) KSO4
2H2O
K=1
S=1
O=4
[ _________ Total]
[ _________ Total]
O = _______
[ _________ Total]
H = _______
5). 2NH4NO3
6). 3Ca(OH)2
N = _______
Ca = _______
[ _________ Total]
O = _______
O = _______
[ _________ Total]
H = _______
7). Na3(PO4)2
8). PbCrO4
Na = _______
Pb = _______
[ _________ Total]
O = _______
Cr = _______
[ _________ Total]
O = _______
9). NH4Cl
10). H2SO4
N = _______
Cl = _______
[ _________ Total]
Ca = _______
O = _______
H = _______
Cl = _______
4). Ca(OH)2
K = _______
P = _______
Subscript
Mg = _______
3). 4K2CO3
H = _______
Coefficient
2). MgCl2
H = _______
C = _______
2H2O
6 total atoms
1). H2O
O = _______
H=4
O=2
total = 6 atoms
H = _______
[ _________ Total]
S = _______
O = _______
[ _________ Total]
11). Mg(FO3)2
12). 2CH3OH
Mg = _______
F = _______
C = _______
[ _________ Total]
O = _______
14). 2H3NCH3Br
Ca = _______
H = _______
[ _________ Total]
N = _______
H = _______
C = _______
O = _______
Br = _______
15). Al(HCO3)3
N = _______
[ _________ Total]
H = _______
C = _______
S = _______
O = _______
O = _______
17). 4Na(O2H)2
Fe = _______
[ _________ Total]
H = _______
P = _______
[ _________ Total]
O = _______
19). 3(NH4)2Cr2O7
20). Ca(C2H2O2)2
N = _______
H = _______
[ _________ Total]
18). 5Fe3(PO4)2
Na = _______
O = _______
[ _________ Total]
16). (NH4)2SO4
Al = _______
H = _______
[ _________ Total]
O = _______
13). Ca(C2H3O2)2
C = _______
H = _______
Ca = _______
[ _________ Total]
C = _______
Cr = _______
H = _______
O = _______
O = _______
[ _________ Total]
21). Fe(OH)3
22). Al(NO3)3
Fe = _____ O = ______ H = _____ [ _______ Total]
Al = _____ N = _____ O = ______ [ _______ Total]