Counting Atoms and Molecules

An element is...

• A substance made up of only one type of atom

• A substance made up of two types of atoms

• The same thing as a compound

A molecule is...

• A substance made up of only one type of atom

• When two or more atoms are chemically bonded together

• Lots of different types of atoms

Tags

NGSS.MS-PS1-1

Which one of these is a molecule of an element?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-1

A compound is...

• When there are lots of atoms

• When two or more different types of atoms are chemically bonded together

• An element

Which one of these is a compound?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-1

What do the subscript (small) numbers tells us in a chemical formula?

• How big the molecule is

• The size of each atom

• How many of each atom we have

• The age of the atoms

Which of the following is a compound?

• Co
• O₂
• C
• CO₂

Tags

NGSS.MS-PS1-1

How many Hydrogen atoms are in H₂O?

• 0

• 1

• 2

• 3

Tags

NGSS.MS-PS1-1

How many atoms are there TOTAL in H₂SO₄ ?

• 6

• 5

• 7

• 3

Tags

NGSS.MS-PS1-1

How many Nitrogen atoms are in the in H₂C₃O₄N₅?

• 2

• 3

• 4

• 5

Tags

NGSS.MS-PS1-1