Download Structure of Atoms

STRUCTURE OF ATOMS
Created by: Mrs. Susan Dube
MATTER AND ATOMS (COPY INTO NOTES)
All matter is made up of atoms
 Atoms are the smallest forms of elements
 Three types of particles make up atoms

STRUCTURE OF ATOMS (COPY INTO NOTES)
Atoms are composed of three types of particles
 Protons – positively charged particles found in
the nucleus
 Neutrons – uncharged particles found in the
nucleus
 Electrons – negatively charged particles that
move around the outside of the nucleus
 Quarks – particles that make up protons and
neutrons
NUCLEUS (COPY INTO NOTES)

Center of the atom that holds the protons and
neutrons together
PROTONS -ATOMIC NUMBER
(COPY INTO NOTES)
Atomic number is the number of protons in
the nucleus
 It’s like the fingerprint of the element
 No two elements have the same atomic number

NEUTRONS
Neutral particles; have no electric charge
 Help make up the nucleus of the atom
 Contribute to the atomic mass
(copy into notes)

QUARKS
Quarks are the tiniest subatomic particles that
make up protons and neutrons
 There are three quarks in every proton and three
quarks in every neutron
 There are six different kinds of quarks
(copy into notes)

ATOMIC MASS NUMBER (COPY INTO NOTES)

Atomic mass number is the total number of
protons and neutrons found in the nucleus
CALCULATING NEUTRONS (COPY INTO NOTES)
To calculate the number of neutrons in an atom,
you subtract the atomic number (which is the
number of protons) from the atomic mass (copy
into notes)
 Ex. Oxygen
 Atomic mass:
16
 Atomic number:
-8
 Number of neutrons:
8
 Therefore, Oxygen has 8 neutrons

WHAT ABOUT ELECTRONS? (COPY INTO NOTES)
Electrons are negatively charged particles
 An element must have a neutral charge in order
to be stable
 Therefore, the number of electrons (negatively
charged particles) is the same as the number of
protons (positively charged particles)
