Counting Atoms

Number of C's in 2Na₂CO₃

• 1
• 2
• 3
• 5

Number of H in 3(NH₄)₂CrO₄

• 4
• 2
• 8
• 24

Number of N in (NH₄)₂CrO₄

• 1
• 2
• 8
• 16

• 1

• 2

• 3

• 4

• 6

• 1

• 12

Calculate the number of Oxygen atoms in Al(OH)₃

• 1

• 2

• 3

• 4

Coefficients in chemical formulas...

• Multiply just the first atom

• Add to the subscripts at the end of the molecule

• Multiply elements without subscripts

• Multiply EVERYTHING!

4CF₂Cl₂

• C = 4, F = 4, Cl = 2

• C = 1, F = 8, Cl = 8

• C = 4, F = 8, Cl = 8

• C = 1, F = 4, Cl = 8

C₃H₅(NO₃)₃

• C = 3, H = 5, N = 3, O = 9

• C = 3, H = 5, N = 1, O = 9

• C = 9, H = 15, N = 3, O = 9

• C = 9, H = 15, N = 1, O = 3

H₂SO₄

• H = 2, S = 4, O = 4

• H = 2, S = 1, O = 4

• H = 8, S = 4, O = 4

• H = 2, SO = 4