Ionic compounds Flashcards
Key concepts in chemistry
anion
Definition
An atom or group of atoms that have gained electrons and become negatively charged. Most anions are formed from non-metals.
aqueous
Definition
Dissolved in water to form a solution. Shown as (aq) in chemical equations.
atom
Definition
The smallest part of an element that can exist.
atomic number
Definition
The number of protons in the nucleus of an atom. Also called the proton number.
boiling point
Definition
The temperature at which a substance rapidly changes from a liquid to a gas.
cation
Definition
An atom or group of atoms that have lost electrons and become positively charged. Most cations are formed from metals.
charge
Definition
Property of matter that causes a force when near another charge. Charge comes in two forms, positive and negative. For example, a negative charge causes a repulsive force on a neighbouring negative charge.
charged particles
Definition
Particles, usually ions or electrons, that carry electrical charges.
compound
Definition
A substance formed by the chemical union of two or more elements.
conduct
Definition
To allow electricity, heat or other energy forms to pass through.
electron
Definition
Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons.
electrostatic force
Definition
A force of attraction between particles with opposite charges.
ionic bonding
Definition
Ionic bonding forms between two atoms when an electron is transferred from one atom to the other, forming a positive-negative ion pair.
ionic compound
Definition
An ionic compound occurs when a negative ion (an atom that has gained an electron) joins with a positive ion (an atom that has lost an electron).
ionic lattice
Definition
The regular arrangement of ions in an ionic substance.
molten
Definition
A term used to describe a liquid substance (eg rock, glass or metal) formed by heating a solid.
polyatomic ion
Definition
Charged particle consisting of two or more atoms joined together.
Which type of elements gain/lose atoms to form ions?
metal atoms lose electrons to form positively charged ions
non-metal atoms gain electrons to form negatively charged ions
Forming positive ions
Metal atoms lose electrons from their outer shell when they form ions:
- the ions formed are positive, with more protons than electrons
- the ions formed have full outer shells
Forming negative ions
The outer shell of non-metal atoms gains electrons when they form ions:
- the ions formed are negative, because they have more electrons than protons
- the ions formed have full outer shells