Comments on: Can some one explain in detail how to write chemical formulas for these problems?- middle school science? http://www.clintsmallband.org/middle-school-science/can-some-one-explain-in-detail-how-to-write-chemical-formulas-for-these-problems-middle-school-science Wed, 25 Jan 2012 15:42:59 -0500 http://wordpress.org/?v=2.8.4 hourly 1 By: hollymolly http://www.clintsmallband.org/middle-school-science/can-some-one-explain-in-detail-how-to-write-chemical-formulas-for-these-problems-middle-school-science/comment-page-1#comment-1639 hollymolly Sat, 13 Feb 2010 11:54:59 +0000 http://www.clintsmallband.org/middle-school-science/can-some-one-explain-in-detail-how-to-write-chemical-formulas-for-these-problems-middle-school-science#comment-1639 This is pretty hard for middle school! But as my Chemistry teacher liked to say, Chem is try (get it? chemistry) Anyways.... -ide is a suffix that means negatively charged, aka has space for taking on positively charged ions. What comes before the suffix is the chemical that is negatively charged. In your case oxygen, sulfur, fluorine, and nitrogen. A *general* rule is that the very last column (starting with He, Ne, etc) has 0 negative charges. The 2nd to last column (starting with F, Cl, etc) has one negative charge. This goes on backwards till you go 4 (or is it 5?) columns backwards. A similar *general* rule is that the first column (starting with H, Li, etc) has one extra positive charge. The second column has 2, and so on. So lithium oxide, for example, has lithium (one positive charge) and oxygen has 2 negative charges. You want the total charge to be zero. So you need 2 lithiums (+1 x 2 = 2) for your one oxygen (-2 x 1 = -2) to get zero (+2 + -2 = 0). So the way that you would write that would be: 2 Li^-1 + O^-2 -> Li_2O (The ^ means superscript and the _ means subscript... you may know that, but I didn't in middle school). See the Wikipedia page below to see the notation for the left hand side to get an idea if you don't know what I'm talking about. Magnesium sulfide would look like: Mg^-2 + S^-2 -> MgS Both have the same but opposite charge so you don't need to double (or triple) up to balance the charges. Hope that helps and good luck. Chemistry really isn't that bad once you get past all the background stuff like what you're doing right now.<br><b>References : </b><br>http://en.wikipedia.org/wiki/Lithium_oxide This is pretty hard for middle school!
But as my Chemistry teacher liked to say, Chem is try (get it? chemistry)

Anyways….

-ide is a suffix that means negatively charged, aka has space for taking on positively charged ions.

What comes before the suffix is the chemical that is negatively charged. In your case oxygen, sulfur, fluorine, and nitrogen.

A *general* rule is that the very last column (starting with He, Ne, etc) has 0 negative charges. The 2nd to last column (starting with F, Cl, etc) has one negative charge. This goes on backwards till you go 4 (or is it 5?) columns backwards.

A similar *general* rule is that the first column (starting with H, Li, etc) has one extra positive charge. The second column has 2, and so on.

So lithium oxide, for example, has lithium (one positive charge) and oxygen has 2 negative charges. You want the total charge to be zero. So you need 2 lithiums (+1 x 2 = 2) for your one oxygen (-2 x 1 = -2) to get zero (+2 + -2 = 0).

So the way that you would write that would be:

2 Li^-1 + O^-2 -> Li_2O

(The ^ means superscript and the _ means subscript… you may know that, but I didn’t in middle school). See the Wikipedia page below to see the notation for the left hand side to get an idea if you don’t know what I’m talking about.

Magnesium sulfide would look like:

Mg^-2 + S^-2 -> MgS

Both have the same but opposite charge so you don’t need to double (or triple) up to balance the charges.

Hope that helps and good luck. Chemistry really isn’t that bad once you get past all the background stuff like what you’re doing right now.
References :
http://en.wikipedia.org/wiki/Lithium_oxide

]]>