How do you remember valencies of elements easily?

Answer 1

valence electrons can be determined by remember the number of electrons in the last shell. this can be done easily like this first ring: 2 second ring: 8 third ring: 8 So if the number is 8 (oxygen) you know there will six valence electrons in the second shell because it will be 2)6) and oxygen will need two more electrons to become stable. or I label the top of my Periodic Table 1 through 8 skipping the transition elements. These numbers can be very helpful. i.e The numbers will represent the number of valence electrons, the normal valency will be what makes it obey octet rule (total of 8) ie Nitrogen is family 5 it will need 3 to make it 8, so normal valency is 3. This is good for all but Hydrogen, because its normal valency is 1. They will also show the charge after ionization (rows 1, 2, and Al the charge will be +1,+2,+3 ; rows 5 through 8, if you minus 8 from the row number you will get the charge, N = -3, O = -2 and so on) This will only get you so far, but in early chemistry it is very helpful. --Cswigert

Answer 2

Look at what column it's under and whatever the the column number is you take that number or the last digit of the column number and that's how many valence electrons are there.

For example. An atom under column 1, has 1 valence electron.

An atom under column 16, has 6 valence electrons.

And so on and so forth, but note. This applies to the main elements you'll be looking at and not the transitional elements.

Answer 3

One way to remember valencies of elements is by looking at their position on the periodic table. Elements in the same group tend to have the same valency. Another method is to practice using flashcards or Mnemonic Devices to help reinforce the valencies in your memory.