Elements and Counting Atoms

Matter can be divided into many categories.

Today we are focused on elements and compounds.​

​​Gold - Au

All elements start with a capitol letter and may or may not have a lowercase letter attached.

Be careful! Not all element names match their symbol. The Latin word for iron is ferrum.

​​Neon - Ne

​​Carbon - C

​​Iron - Fe

​Element : a substance that cannot be broken down into smaller parts or changed into other substances

water

Look at the formula for water and hydrogen peroxide.

Adding one atom of oxygen changes the whole thing!

​​baking soda

hydrogen peroxide

sugar

​Compound : two or more different elements bonded in a specific ratio

Categorize

Options (13)

K

KCl

Na

Fe

O2

H

Ar

H2O

CO2

NaCl

CH4

CaCO3

Fe2O3

Organize these options into the right categories

Element

Compound

Counting atoms in a formula

H₂0

Hydrogen - Blue
Oxygen - white
Carbon - yellow
Potassium - green

Build a molecule of water!

2H₂0

Hydrogen - Blue
Oxygen - white
Carbon - yellow
Potassium - green

What would this look like?

K₂CO₃

Hydrogen - Blue
Oxygen - white
Carbon - yellow
Potassium - green

Build a molecule of potassium carbonate!

​Let's Eat Spicy Potato Chips!

​Element	​Subscript	​Parenthesis	​Coefficient	​Total
​	​	​	​	​
​	​	​	​	​
​	​	​	​	​

​We'll use this chart to calculate all of the atoms in a formula!

Draw

Calculate the number of atoms of each element as well as the total number of atoms.

NaC₂H₃O₂

Draw

Calculate the number of atoms of each element as well as the total number of atoms.

4Ca(OH)₂

Multiple Choice

How many elements are in C₆H₁₂O₆?

• 1

• 2

• 3

• 4

Multiple Choice

How many total atoms are in the compound C₂H₈O ?

• 11

• 2

• 8

• 1

Multiple Choice

Which is the correct formula for:
 three hydrogen (H)
one sulfur (S)
four oxygen (O)

• H₃SO₄
• HSO₄
• H₄S₃O
• H₂O

Multiple Choice

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