How many valence electrons are there in Ag?

Question

How many valence electrons are there in Ag? And basically, how do you determine valence electrons in general?

Answer 1

Short answer:
Depends how you define "valence".

Long answer:
A couple of people have said "look at the group number". That's not so helpful. Most people use a standard 1-18 across the table for Group numbers, which means carbon is in Group 14, and it doesn't have 14 valence electrons. If you use an older style notation with Roman numerals, then Fe Co and Ni are *all* in Group VIII, and they obviously can't have the same number of valence electrons, because they're in different columns. So that's no good.

Another poster said -- write out the electronic configuration, and the valence electrons are those of the highest principal quantum number. C is (1s)2(2s)2(2p)2, so that's four e- in the n=2 shell, so four valence electrons. Na is (1s)2(2s)2(2p)6(3s)1, so that's one e- in the n=3 shell, so one valence electron.

Which is fine for main group elements, those is the s- and p-blocks of the table. As a quick trick it works out to # valence e- = Group number (s block) or Group number – 10 (p block).

But that method is a train wreck for d-block or f-block.

The trouble with a formulaic definition is that it misses the point. Valence electrons are those that get involved in chemistry. They might be lost or gained or shared to form bonds, or they might just sit in the frontier orbitals of a compound and change the properties, but the # or valence electrons are those that determine the chemistry -- which is why the periodic table, acting as a map to valence electron configuration, is such a useful organizing tool. And d-block elements tend to use their d-electrons to do chemistry (surprise).

So saying that Ag has only one valence electron because it only has one electron in the n=5 shell is somewhat misleading. An argument could be made that this is a reasonable description for Groups 11 and 12, the argument doesn't extend well to iron or molybdenum or vanadium. (Or, really, even copper or gold, for which the answers determined by this method would presumably be the same. Cu does a lot of Cu(II) chemistry and the 9 remaining electrons are critical to everything that happens. Gold does a lot of Au(III).) Those elements use their d-electrons to make covalent bonds all the time, so demoting them to "core" and leaving only the (usually lost) s electrons as "valence" doesn't describe the chemistry, and so misses the point.

So, better rule, subject in some cases to subjective differences of opinion as to what the word "valence" really should be telling you:

s-block: highest n value only, valence e– = Group number
p-block: highest n value only, valence e– = Group number – 10 (assuming 1-18 notation)
d-block: include both s and d electrons, valence e– = Group number
f-block: include all of s, d, and f electrons, more or less.

If you follow that, Ag has 11.

But many chemists would be happy with "1".

Depends how you define "valence".

Answer 2

Ag ; [Kr].4d10.5s1

Thus, it has 1 valence electron..

Always look at the electron configuration..The nos of electrons in the outer-shell (Sum of electrons from the same quantum shell) is the nos of valence electrons

Example, Oxygen: 1s2 2s2 2p4
Valence electron is the sum of 2+4 = 6 (2s and 2p electrons)

Answer 3

OK, valence is the nuber of electrons in the outer shell, so the group number is the nu,ber of valance electrons. .

Answer 4

Look at the top of the P. ToE.

The number, 1.2.3...7 it the num of V Elc.

Answer 5

5-none