IONS

Ions: 2 types Charged atoms due to the atom losing or gaining electron(s) to make an octet Cation: positively charged ions - think of the t as a + sign Anion: Negatively charged ions - think of an ANtagonist in a book

Octet Rule All atoms can ONLY hold up to 8 valence electrons. All atoms are trying to get 8 valence electrons by gaining, losing, or sharing electrons. Atoms want to give away or take electrons in order to wind up with 8 electrons. They do through bonding. 8 is your magic number

Ions: Remember how many valence electrons each group has The noble gases are already an octet and will NOT gain or lose any electrons; why they are mostly unreactive All other families will lose or gain to get 8 valence electrons depending on how many valence electrons they already have.

Ions: Alkali Family has 1 valence electron Sodium: 1s22s22p63s1 It can either gain 7 or lose 1 valence electron(s) Sodium Ion: 1s22s22p6 8 valence electrons It is easier (less energy)for the alkali metal family to lose 1 electron to form an octet, so it will form a +1 charged cation. Sodium: 11 electrons and 11 protons = 0 Sodium Ion: 10 electrons and 11 protons = +1

Cation or Anion? Alkaline Earth Metals: have 2 electrons so they gain 6 or lose 2 They will lose 2 electrons to form a +2 cation Boron Family: have 3 electrons so they gain 5 or lose 3 They will lose 3 to form a +3 cation Carbon Family: Have 4 electrons so they gain 4 or lose 4 They will either gain or lose 4, forming either a +4 cation or a -4 anion. Typically they will form a +4 cation, or no ion at all. Nitrogen Family: Have 5 electrons so they can gain 3 or lose 5 They will gain 3 electrons to form a -3 anion This is due to the relatively high electronegativity of the Nitrogen family. It is not as difficult, (requires less energy) for it to attract 3 electrons, opposed to an atom that would need to attract 5 or more. When an atom becomes an anion (negatively charged) it is ending changes to -ide

Cation or Anion? Oxygen Family: Have 6 electrons so they can gain 2 or lose 6 They will gain 2 electrons forming a -2 anion This is due to the relatively high electronegativity of the Nitrogen family. It is not as difficult, (requires less energy) for it to attract 2 electrons, opposed to an atom that would need to attract 5 or more. When an atom becomes an anion (negatively charged) it is ending changes to –ide Oxygen becomes oxide Halogen Family: Have 7 electrons so they can gain 1 or lose 7 They will gain 1 electrons forming a -1 anion This is due to the relatively high electronegativity of the Nitrogen family. It is not as difficult, (requires less energy) for it to attract 1 electrons, opposed to an atom that would need to attract 5 or more. Chlorine becomes chloride

Cation or Anion? Noble Gas Family: Have 8 valence electrons so they won’t gain 8 or lose 8. They will not form any ions

Labeling Ions: The +/- charge and the number that accompanies it is known as an atoms oxidation number:

Element Element Symbol # of valence electrons Oxidation Number Charge Type of ion formed Ion symbol Sodium Ca Fluorine