Page 11 - Science Course 1 (Book 2)

Mo7-L1a: What is a Substance?

Negatively charged Key Concept
particles, or electrons,
move quickly throughout What is a Substance?
an area around the
nucleus called the What is a Substance?
electron cloud.

Not all atoms have the
same number of protons,
neutrons, and electrons

Substances

A substance is matter with a composition that is
always the same.
This means that a given substance is always made
up of one or more atoms in the same combinations.

Two type of substances are elements and compounds.

SUBSTANCE

ELEMENT COMPOUND

SUMMARY
What is a Substance?

A substance has the same composition An atom is the smallest part of an element that
throughout. has its properties.

A substance is either an element Atoms contain protons, neutrons, and
or a compound. electrons.

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