PRESENTATION OUTLINE
Atoms and Periodic Table Vocabulary
Atomic number-
The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
Atomic mass-
The mass of an atom of a chemical element expressed in atomic mass units.
Mass number-
The total number of protons and neutrons in a nucleus.
Subatomic particle-
A particle smaller than an atom, a neutron, or a cluster of such particles.
Electron cloud-
It is used to describe where electrons are when they go around the nucleus of an atom.
Energy level-
The fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have.
Valence electron-
Valence electron is an outer shell electron that is associated with an atom.
Chemically stable-
Chemical stability when used in the technical sense in chemistry, means thermodynamic stability of a chemical system.
Chemically reactive-
Reactivity then refers to the rate at which a chemical substance tends to undergo a chemical reaction in time. In pure compounds, reactivity is regulated by the physical properties of the sample.
Conductor-
A material or device that conducts or transmits heat, electricity, or sound, especially when regarded in terms of its capacity to do this (humans conduct heat an can conduct electricity).
Insulator-
A substance that does not readily allow the passage of heat or sound.
Semiconductor-
A solid substance that has a conductivity between that of an insulator and that of most metals, either due to the addition of an impurity or because of temperature effects.
