Page 13 - Science Course 1 (Book 2)

Mo7-L1b: What are the Types of Pure Substances?

COMPOUND

Carbon Dioxide – CO2

Compounds are atoms of different elements
bonded together. The types of atoms in a
A compound is a type of substance containing compound always are in the same combination.
atoms of two or more different elements chemically
bonded together.

The combination of symbols and numbers that Chemical formulas show the different atoms that
represents a compound is called a chemical formula.
make up a compound, using their element symbols.
Chemical formulas also help explain how the atoms
oxygen hydrogen carbon nitrogen chlorine f uoride combine.

A compound often has different properties from the
individual elements that compose it.

NH2 C2 C3 CN CH

Symbol for hydrogen

HCN C2H2 C2H6 NH3 Symbol for carbon Symbol for oxygen

C6H12O6

Six atoms Six atoms
If a substance contains only one type of atom, it of carbon of oxygen
is an element. If it contains more than one type of Twelve atoms
atom, it is a compound. of hydrogen

SUMMARY
What are the Types of Pure Substances?

An element is a substance that consists of just one
type of atom.

A compound is a type of substance containing
ELEMENT
atoms of two or more different elements chemically
bonded together.
Hydrogen – H2

The atoms of some elements
exist as groups. All atoms in a
group are the same type
5