Counting Atoms 10/10

How many different elements are present in the chemical formula KBr?

• 1

• 2

• 3

• 4

What are the little numbers called?

• Coefficients

• Subscripts

• Superscripts

In the chemical formula C6H12O6, how many hydrogen atoms are present?

• 6

• 12

• 1

• 24

What are the big numbers called?

• Coefficients

• Subscripts

• Superscripts

If a chemical formula is written as 2NaCl, how many sodium (Na) atoms are there?

• 1

• 2

• 3

• 4

In the chemical formula Al2(CO3)3, how many oxygen (O) atoms are present?

• 3

• 6

• 9

• 12

Practice using this part of Chemical Compound (NH₄)₂SO₄:

(NH₄)₂

How many Nitrogens are there in the formula?

• 1

• 2

• 3

• 4

Answer explanation

There are 2 because the 2 from outside the paratheses multiplies to everything in the parentheses.

Using the first half of (NH₄)₂SO₄

(NH₄)₂

How many hydrogen atoms are there?

• 2

• 4

• 6

• 8

Answer explanation

The 2 outside the parentheses multiplies to everything inside the parentheses, meaning the H₄ is multiplied by 2, thus is 8.

Using the 2nd half of (NH₄₎₂SO₄

SO₄

How many Sulfur atoms are there?

• 1

• 2

• 3

• 4

Using the 2nd half of (NH₄₎₂SO₄

SO₄

How many Oxygen atoms are there?

• 1

• 2

• 3

• 4