Positively charged subatomic particle. Contained inside the nucleus. Neutrons and Protons weigh roughly the same (1 atomic mass unit).
The center of an atom. Contains the protons and neutrons. Since neutrons have no charge and protons are positively charged, the nucleus has an overall positive charge.
Neutrally charged subatomic particle. (No charge) Contained inside the nucleus. Neutrons and Protons weigh roughly the same (1 atomic mass unit)
Negatively charged subatomic particles. Electrons can be found in the space around the nucleus. This area is often called the electron cloud. Electrons have NO mass.
Identifies an element. The number of protons. For a neutral atom, the number of electrons will equal the number of protons. For an ion (charged atom) the number of electrons will not be the same as the atomic number.
Atomic Mass Number
Also known as the Mass Number or Atomic Mass.
How to calculate neutrons:
# of Neutrons = Atomic Mass Number - Atomic Number
Atoms of the same element which have a different Mass Number due to a differing number of neutrons.
The symbol for an Isotope is the element symbol followed by the Mass Number, for example:
Na-23 and Na-24
Atoms or groups of atoms with a charge. To have a charge an atom must have gained or lost electrons. If an atom gains electrons it becomes negatively charged. If an atom loses electrons it will become positively charged.
Positively Charged Ions. In general, cations are metals.
Negatively charged Ions. Anions are negatively charged because they have gained an electron(s) (electrons are negative). In general, anions are nonmetals.
Horizontal row on the periodic table.
Group or Family
Vertical Column on the periodic table. Elements in the same family have similar properties.
Electrons found on the outer energy level. Represented by Roman Numerals. Transition Elements do not have Roman Numerals which denote their valence electrons.
Above groups/families Roman Numerals represent the number of valence electrons.
When writing the name of an ionic compound which includes a transition metal a Roman Numeral is used to denote the quantity of positive charge associated with that transition metal.
Principle Energy Level
The possible locations around an atom where electrons having specific energy values (quantum number) may be found. Divided into sublevels s, p, d, and f.
To the left side of the periodic table (left of the zig zag line).
Usually, solids at room temperature.
Good conductors of heat and electricity.
High melting and boiling points.
To the right hand side of the periodic table (right of the zig zag line).
Not good conductors.
Low melting and boiling points.
Have properties of both metals and nonmetals.
Group 1 Nonmetal
Able to be hammered or pressed permenately out of it's original shape without breaking or cracking.
A material which permits the flow of energy. A material which allows the flow of charged particles is an electrical conductor. A material which allows the transfer of thermal energy is a thermal conductor or heat conductor.
Capable of being drawn out into a wire or thread.