Chemistry: Atoms/Bonding - Term 2

Proton

Positively charged particle located in the nucleus with a mass of 1.

Neutron

Neutral particle located in the nucleus with a mass of 1.

Electron

Negatively charged particle orbiting the nucleus with a negligible mass of 1/1840.

Atomic Number

The number of protons in the nucleus, defining the element.

Mass Number

Total mass of an atom, calculated by protons + neutrons.

Isotopes

Atoms of the same element with different numbers of neutrons and therefore different mass numbers.

Anion

Negatively charged ion (more electrons than protons).

Cation

Positively charged ion (fewer electrons than protons).

Electron Configuration

Representation of the number of electrons in each shell of an atom or ion, listed from innermost to outermost.

Alkali Metals

Elements in group 1 of the periodic table, known for reacting violently with water.

Alkaline Earth Metals

Elements in group 2 of the periodic table, forming basic solutions when combined with water.

Transition Metals

Groups 3-12 on the periodic table, known for forming colored ions and compounds.

Halogens

Elements in group 17 on the periodic table, reacting with metals to form ionic compounds called salts.

Noble Gases

Elements in group 18 on the periodic table, unreactive due to a stable valence shell.

Metalloids

Elements with properties of both metals and nonmetals, found in a diagonal line separating metals and nonmetals on the periodic table.

Metallic bonding

An attraction/bond between positively charged metal ions and delocalised electrons

Ionic Bonding

Bonding that occurs through electrostatic attraction between a cation and an anion.

Delocalised Electrons

Can freely move through a metal without being attached to an atom