Understanding Chemical Formulas and Atoms

What does a chemical formula tell us about a substance?

• The color of a substance

• The taste of a substance

• The ingredients and amounts of a substance

• The weight of a substance

In the chemical formula H₂O, what does the small number '2' tell us?

• There are 2 oxygen atoms

• There are 2 water molecules

• There are 2 hydrogen atoms

• There are 2 types of elements

If a chemical formula shows an element without a subscript number, how many atoms of that element are there?

• Zero

• One

• Two

• It depends on the other numbers

What is the correct way to identify an element symbol in a chemical formula?

• It is always a single capital letter

• It is always a single lowercase letter

• It is one capital letter or one capital letter followed by one lowercase letter

• It is any combination of letters

How many Lithium (Li) atoms are in the chemical formula Li₂O?

• One

• Two

• Zero

• Three

How many oxygen atoms are in the chemical formula for aspirin, C₉H₈O₄?

• 9

• 8

• 4

• 1

In the chemical formula H₂SO₄, how many sulfur (S) atoms are there?

• One

• Two

• Four

• Zero

How many magnesium (Mg) atoms are in the chemical formula for asbestos, H₄Mg₃Si₂O₉?

• 4

• 3

• 2

• 9

In a chemical formula with parentheses, like C₇H₅(NO₂)₃, what does the small number outside the parentheses mean?

• It only applies to the last element inside the parentheses

• It applies to all elements outside the parentheses

• It multiplies the number of atoms for every element inside the parentheses

• It means there are three separate molecules

How many hydrogen atoms are in the chemical formula for fertilizer, Ca(H₂PO₄)₂?

• 1

• 2

• 4

• 8