2. Matter
• Matter occupies space and has
mass
• Most things in our environment
are matter
• Matter can be described using
volume, mass, and density
• Matter can occupy different
states and can change state
3. Atom
• The smallest particle of
matter in an atom
• Atoms make up everything
• Atoms combine in different
ways to form elements and
compounds
4. Types of matter
• Element: a substance that
cannot be broken down into
simpler substances, such as
oxygen
• Compound: a substance made
of multiple elements linked
together, such as water which
is hydrogen and oxygen
together
5. Atomic structure
• Atoms are made up of three
different particles
• Protons have a positive charge
• Neutrons have no charge
• Protons and neutrons group
together in the nucleus
• Electrons have a negative
charge
• Electrons orbit the nucleus
6. Electrons
• There are multiple regions
around the nucleus in which
electrons can move
• These are called energy levels
because the neutrons in each
level have different amounts of
energy
• Each energy level can hold a
set number of electrons
8. Isotopes
• Atoms in this element have the
same number of protons, but
the number of neutrons is
different
• Radioactive isotopes have an
unstable nucleus that can
break apart
• The nucleus breaking gives off
energy