Deca=10
Decades
Decalog
Decagon
Nona=9
nonadult
nonacid
nonagon
Octo=8
Octogon
Octopus
October
hept=7
Heptameter
Heptagon
Heptane
Hex=Six
Hexagon
Hexahydrate
Hexahedrons
penta=five
pentagon
pentarch
repentant
tetra=four
tetragons
tetraploid
tetramer
tri=three
triangle
airstrike
atria
di=two
dictator
abdicate
acidify
mono = one
monopoly
ammono
monohull
Neon Calcium
Ne Ca
10 20
Potassium Fluroine
K F
19 9
Oxygen Argon
O AR
8 18
Nitrogen Chlorine
N CI
7 17
Carbon Sulfur
C S
6 16
Phosphorus Boron
P B
15 5