6-Ionic and Molecular Compounds

Electrons are transfered

An Ionic compound

Metal+ nonmetal=…

An ionic compound

Electrons are shared

A molecular compound

Nonmetal+Nonmetal=…

A molecular compound

In ionic compounds, one atom has a very strong pull on electrons, while the other has a very weak pull. This happens most often when…

A metal (which wants to give up electrons) bonds with a nonmetal (which wants to take electrons)

In molecular (covalent) compounds, the bonding atoms have similar pulls on electrons. Neither atom is…..

strong enough to completely steal an electron from the other, usually because the atoms are both nonmetals.

Atoms lose, gain, or share electrons to get…

8 valence electrons (The Octet Rule)

An exception to the Octet Rule is that….

Helium and Hydrogen only want 2 and the octet rule does not apply to transition metals.

Cations

Lose electrons —> get smaller than their original atom.

Anions

Gain electrons —→ get larger than their original atom.

If you see 3 or more elements (like Na2SO4), then you are dealing with a (BLANK) ion.

Polyatomic

(In SO2- over 4 and SO4- over 3) -ate vs -ite: The one ending in -ate has…

more oxygen atoms

(In SO2- over 4 and SO4- over 3) -ate vs -ite: The one ending in -ite has…

Fewer oxygen atoms

Only use them if you need more than one polyatomic ion to balance the charge

Parentheses

Zinc, Cadmium, and Silver are…

Transition metals that have fixed charges so we DON’T use Roman numerals for them.

In molecular compounds, drop the "a" or "o" at the end of a prefix if….

the element starts with a vowel (e.g., carbon monoxide, not mono-oxide; tetroxide, not tetra-oxide) (Vowel Drop Rule)

Roman Numeral = (BLANK), not (BLANK)

-charge, not subscript, and If you see "Iron(III) oxide", the (III) means {Fe}^3+, it does not automatically mean {Fe subscript 3) You still have to balance it with Oxygen ({O^2-), giving you Fe subscript 2 and O subscript 3