Changes

==Structure==

==Structure==

Atoms are comprised of three subatomic particles: positively charged [[proton|protons]], electrically neutral [[neutron|neutrons]] and negatively charged [[electron|electrons]]. Protons and neutrons are contained in close proximity in the centre of an atom, forming the [[nucleus]]. Electrons inhabit the space around the nucleus, and are arranged around it in a series of layers, known as [[electron shell|shells]] or energy levels.

Atoms are comprised of three subatomic particles: positively charged [[proton|protons]], electrically neutral [[neutron|neutrons]] and negatively charged [[electron|electrons]]. Protons and neutrons are comprised of quarks and are contained in close proximity in the center of an atom, forming the [[nucleus]]. Electrons inhabit the space around the nucleus, and are arranged around it in a series of layers, known as [[electron shell|shells]] or energy levels.

===Atomic Number===

===Atomic Number===

===Ions===

===Ions===

Atoms are normaill electrically neutral; thry have no charge. However, elctrtons in the [[valence shell]] can be gained or lost (depending on the element and the conditions) to form an [[Ion|ion]]. An atom that loses electrons becomes positively charged and is known as a cation. An atom that gains electrons electrons becomes negatively charged and is known as an anion.

Atoms are normally electrically neutral; thry have no charge. However, elrctrons in the [[valence shell]] can be gained or lost (depending on the element and the conditions) to form an [[Ion|ion]]. An atom that loses electrons becomes positively charged and is known as a cation. An atom that gains electrons electrons becomes negatively charged and is known as an anion.

Many common substances are made up of ions. For example, [[sodium chloride]] (NaCl), otherwise known as table salt, is made up of [[sodium cations]] (Na⁺) and [[chlorine]] anions (Cl^-) in equal proportions. The negatively charged chlorine ions are attracted to the positively charged sodium ions, forming an [[ionic bond]]. This results in a lattice structure, which is responsible for sodium chloride being crystalline in its solid state.

Many common substances are made up of ions. For example, [[sodium chloride]] (NaCl), otherwise known as table salt, is made up of [[sodium cations]] (Na⁺) and [[chlorine]] anions (Cl^-) in equal proportions. The negatively charged chlorine ions are attracted to the positively charged sodium ions, forming an [[ionic bond]]. This results in a lattice structure, which is responsible for sodium chloride being crystalline in its solid state.