Explanation:
These prefixes are very commonly used in naming chemical compounds.
Di- means two.
For example, carbon dioxide's formula is be written as [tex]\text{CO}_2,[/tex] and it has 2 oxygen atoms, hence "di-oxide."
Tetra - means four.
For example, carbon tetrachloride's chemical formula is written as [tex]\text{CCl}_4[/tex], and there are four chlorine atoms
Deca- means ten
For example, lanthanum decahydride's chemical formula is written as [tex]\text{LaH}_{10}.[/tex] In this case there are 10 hydrogen atoms for every lanthanum atom.
Hepta - means seven
For example, iodine heptafluoride is written as [tex]\text{IF}_7[/tex]. Note the seven fluorine atoms attached to the iodine atom, hence the name "hepta-fluoride."
