Sames Physical Science

Parts of an Atom

Nucleus: Center of the atom
-most of mass of atom is located here
-positively charged
-made up of protons & neutrons

Electron: negatively charged particle that surrounds the nucleus in a region

Electron Cloud: Region where electrons are found surrounding the
nucleus

Energy Level: The different areas where electrons move about in an orbit around the nucleus. Closer the orbit, lower the energy
level of the electrons. Further from the nucleus, more energy electrons have.

Proton: positively charged particle with a mass of 1amu located in the nucleus of an atom.

Neutron: particle with no charge, with a mass of 1amu located in the nucleus of an atom

Atomic Number: number of protons in the atom.
Atomic Mass: sum of number of protons and neutrons in the atom.

How to find the number of neutrons in an atom: subtract the atomic number from the atomic mass (make sure you have rounded the atomic mass to the nearest whole number)

How to find the number of electrons in an atom: if an atom is neutral, the number of electrons must equal the number of protons.

Ion: an atom that has gained or lost electrons resulting in a positive or negative charge

Isotope: an atom that has a different number of neutrons in it’s nucleus