Aww... I can't remember the symbols an valencies in chemistry!! :confused:

The valencies are easy to remember . The 8 main collumns go 1 2 3 4 3 2 1 0 as in first collumns 1 valency seconds 2 and 7th its 1 etc.

And as for the valencies of tramsition elements you have to assum they are always 2 unless stated

Hey Aurelie!! Welcome to AMHD! :) :) :)

Generally, the symbols of elements are made up of the letters in the element's name.

For example, hydrogen is H, oxygen O, nitrogen N, carbon C.

Now, because there are more than one element starting with the same letter, you have symbols using two letters in the name of the element, like helium He, which are the first two letters in helium and which is not H because H is already taken for hydrogen. Others are cobalt Co, chlorine Cl.

Some symbols are directly written in two letters, even if the first letter alone does not exist. These include:
Argon Ar, Arsenic As, Astatine At, Aluminium Al.

Finally, you have exceptions for some elements, which have symbols according to their latin name like sodium Na (for Natrium), copper Cu (from cuprum), potassium K (from kalium)

Don't so much worry about now remembering them, this will come with practice.

Ok, now to the valencies.

If you have a periodic table with you, try to locate the elements you know already, and their valencies.

You'll notice that sodium, potasssium and hydrogen have a valency of 1 and are both in group 1.

Group II elements will have valencies of 2. Group III, valencies of three. Group IV valencies of 4.

However, group V will have valencies of 3, group VI valencies of 2, group VII valences of 1 and group VIII or 0 valency of zero.

Post back if you want more explanation, more details or if there's something you don't understand, OK?

Hmm... yeah... :)
Cave dire mone comprend... ;)
Tinquiete... :D

Hum, try to reply in english... nobody else from me understands creole here (what I think)... lol

OK... do like I understood... :D
No "trACAS" xD

It really is quite simple.

The elements in group 1A of the periodic table tend to have valences of 1 (H, Li, Na, K, Rb, Cs, Fr).

The elements in group 2A of the periodic table tend to have valences of 2 (Be, Mg, Ca, Sr, Ba, Ra)

The elements in group 3A of the periodic table tend to have valences of 3 (B, Al, Ga, In, Tl).

The elements in group 4A of the periodic table tend to have valences of 4 (C, Si, Ge, Sn, Pb).

It goes backwards from groups 5A to 7A.
The elements in Group 5A tend to have valences of 3 or sometimes 5 (N, P, As, Sb, Bi), and then tend to form negative anions rather than cations.

Same for group 6A (valence of 2) and 7A (valence of 1). Group 7A is the halogen group (F, Cl, Br, I, As). They almost always form negative anions (Cl-, for example).

Group VIII are the noble gases. They don't react much, if at all. So, their valence is 0.

Re-read Unknown008's answer, above, and see if it doesn't make more sense now.

You do have to spend some time looking at the periodic table and memorizing the symbols.

What's so hard about this?

Group 1A - valence 1
Group 2A - valence 2
Group 3A - valence 3
Group 4A - valence 4
Group 5A - valence 3
Group 6A - valence 2
Group 7A - valence 1

Group 8 - unreactive. Valence 0.

Unfortunately, you do have to learn the symbols by rote memorization. I know of no other way to do that.