Ions
atom An atom is the simplest particle of an element that can exist on its own in a stable environment. tend to lose or gain electronSubatomic particle, with a negative charge and a negligible mass relative to protons and neutrons. to form a full outer shell.
An ionA charged particle formed when an atom gains or loses electrons. is a charged particle. They are formed when atoms gain or lose electrons to form a full outer shell. Ions are charged because the number of protons is different from the number of electrons.
A molecular ion is a particle made of more than one atom that has an overall positive or negative charge.
- A negative ion is called an anionA negative ion..
- A position ion is called a cation A positive ion. .
Simple ions have full outer shells, and the stable electronic configurationThe order electrons are arranged in different shells. of the noble gasesAn element placed in Group 0 of the periodic table, which starts with helium and ends with radon. They do not react easily with other elements..
Positive ions are usually formed from metal atoms and negative ions are usually formed from non-metal atoms.
A chemical bond can form between oppositely charged ions 鈥 this is called an ionic bond.