Page 12 - Science Course 1 (Book 2)

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

Each type of atom contains a different number of
Mo7-L1b What are the Types of Pure protons in its nucleus.
Substances
KEY CONCEPTS:
1. How do atoms and elements differ?

Vocabulary A-Z

Let us learn some vocabulary

Element
a substance that consists of only one type of atom.

The number of protons in an atom is the atomic
number of the element.

Compound
a substance containing atoms of two or more
different elements chemically bonded together.

H2O NH3
(Water) (Ammonia) Each element on the periodic table consists of just
one type of atom.

Let’s Begin

Substances

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

Because there are about 115 known elements, there What are the Types of Pure Substances?
are about 115 different types of atoms.
How do atoms and elements differ?
2 4.00260 10 20.179 18 39.948
He Ne Ar

Helium Neon Argon
36 83.80 54 131.30 86 (222)
Kr Xe Rn

Krypton Xenon Radon
4