Created by: Mrs. Susan Dube 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)