Ionic compounds form when a metal and a nonmetal transfer electrons from the metal to the nonmetal. The atoms become positive cations and negative anions. The ions are wildly attracted together (like magnets). To name them we follow simple rules:
First: State the metal name.
Second: The nonmetal name changes to end in an -ide sound.
Sodium + chlorine make sodium chloride.
Magnesium + oxygen form into magnesium oxide.
In our class, all the non metal anion names are: nitride, oxide, fluoride, phosphide, sulfide, chloride, bromide and iodide. There are no more monoatomic nonmetals that form ions in our class.
Transitional Metals can make more than one kind of cation, which is a little funky and a little tricky. If you don’t GUESS and you use your periodic table, this is easy. For example, Pb is lead, and it makes a Pb+2 or a Pb+4 cation. They’re called Lead (II) cation and Lead (IV) cation. The Roman Numeral names the type of cation that forms. Lead ALWAYS gets a roman numeral name, ALWAYS. The nonmetal anions work the same way as they did above.
Then when 2 or more NONMETALS bond they bond differently: they make covalent bonds, because they SHARE ELECTRONS, and we’ll learn to name them as well.
We need to keep in mind just 3 molecules to keep track of the rules of naming them: H2O, CO2 and CO. These are (water) dihydrogen monoxide, carbon dioxide, and carbon monoxide.
The naming rules are:
FIRST NAME RULE: say the name of the atom if it’s a “single” atom,
or use a prefix if it’s a multiple.
SECOND NAME RULE: always use a prefix.
Learn the 10 prefixes and use them as needed.
Sometimes there are bigger ions, called POLYATOMIC ions, all listed in table E.
These NEVER change the names they are given, they’re special.
The most important thing for naming is LOOK: is the first atom a metal (then it’s ionic).
Is the first atom a nometal (then it’s molecular).
Naming Compounds Slides (something to think about)
The first chemistry that you ever knew. Water has a formula of H2O, with two hydrogen atoms and one oxygen atom. The "2" means 2 hydrogen atoms. No number after the capital "O" means only one atom of oxygen. This is MOLECULAR because there are NO METALS.
The rest of the early chemistry, table salt is sodium chloride, one atom of sodium and one of chlorine. No numbers means ONE OF EACH. This is IONIC because sodium is a metal.
One of the most produced molecules in the world is NH3, or AMMONIA. No metals so this is also molecular, NOT IONIC. One nitrogen atom bonds to three hydrogen atoms.
MgO stands for one atom of magnesium (a metal) and one of oxygen (a nonmetal). This stuff, magnesium oxide is IONIC.
HCl stands for one atom of H, and one of Cl. It's called hydrogen monochloride, and it's NOT IONIC because there are NO METALS. In water you'd call the mixture hydrochloric acid. It's not acid unless it's in water.
CaCl2 is calcium chloride. Calcium is a metal, this is IONIC. One calcium atom and two chlorine atoms bonded together into a single UNIT of an ionic compound.
This is how CH4 bonds together. It's also called methane, or BUNSEN BURNER GAS. No metals, this is MOLECULAR.
This is copper (II) sulfate. Copper is a transitional metal that can make more than one cation. Here it's the Cu+2 ion, so Roman numeral two also. It's ionic. Sulfate is on Table E, it's a polyatomic ion.
Sodium dichromate practically begs to be yelled out loud, what a neat name! 2 sodium ions bond with a polyatomic ion called dichromate from Table E.
Ammonium nitrate: both of these are on table E, a polyatomic cation (ammonium) and a polyatomic anion (nitrate). One of each, and the total atoms include one nitrogen and four hydrogens bonded with one more nitrogen and three oxygen atoms!
This is way to hard to understand, but it tastes great. It's sucrose, or table sugar. All that is just a bunch of carbon atoms bonded to oxygen atoms and hydrogen atoms. Some bonds are hidden with shortcuts you don't know about (yet). Get psyched, if you can eat it, you can learn about it!
I put this one here because it has a cool name, sodium thiosulfate. It's ionic, and the thiosulfate is on Table E since it's a POLYATOMIC ion.
With methane (natural gas) one central carbon atom shares electrons with four hydrogen atoms. This MOLECULE makes four different bonds, and since it's molecular, we use the prefix naming system to call it carbon tetrahydride. (Methane is a common name).