Atom and Subatomic Paricles

Introduction to

Atoms Subatomic

Particles

Activity: Cutting Up a Post-it Note

To begin, let's think about how
small we can make something by cutting it into smaller and smaller pieces.

Atoms: The Building
Blocks of Matter

Everything you see around you
is made up of atoms. These are
the smallest units of matter that
still have the properties of an
element.

Multiple Choice

What are the building blocks of all matter?

• Protons

• Atoms

• Dirt

• Electrons

Subatomic Particles:
Even Smaller than
Atoms

Atoms are not the smallest
particles. They are made up of
even smaller particles: protons,
neutrons, and electrons.

Protons, Neutrons, and Electrons

● Protons have a positive

charge and are found in
the nucleus.

● Neutrons have no charge

and are also in the
nucleus.

● Electrons have a

negative charge and orbit
the nucleus.

Valence Electrons and
Electron Shells

Electrons are found in energy
levels or shells around the
nucleus. The first shell can hold
up to 2 electrons, the second up
to 8, and the third up to 18.

2 X 8 X 18

Multiple Choice

What are Valence Electrons?

• Electrons in the inner shell

• Electrons that aren't attached to any atom

• Electrons in the outer shell

• Non-reactive Electrons

Atomic Number and Atomic Mass

The atomic number of an
element tells us the
number of protons in the
nucleus. The atomic mass
is the sum of protons and
neutrons.

Multiple Choice

The number on top of the element symbol is the.......(smaller number)

• the number of neutrons in the element

• Atomic mass

• Just a random number

• Atomic number

Multiple Choice

amu stands for

• Atom Member Unit

• Atomic Mass Unit

• A Massive Unit

• Atomic Mass Uncovered

Different Atoms, Different Elements

Not all atoms are the same.
Different elements have
different numbers of protons,
neutrons, and electrons,
which determine their
properties and the things
they make up.

Multiple Choice

All atoms are the exact same

• True

• False

Neutrons and Atomic
Stability

We can determine the number
of neutrons by subtracting the
atomic number from the atomic
mass. The balance between
protons and neutrons affects
the atom's stability.