What is the number of valence electrons in tin?

To understand the concept of valence, we first need to know about valence electrons. These are the electrons present in the outermost shell (valence shell) of an atom.

Let’s take an example:

• Lithium (Li): Its atomic number is 3. So, it has 2 electrons in the first shell and 1 electron in the second shell. The second shell is the valence shell, and it contains 1 valence electron.

Now, consider Tin (Sn):

• Tin is placed in Group 14 of the periodic table. This means it has 4 valence electrons in its outermost shell.
• The atomic number of tin is 50, so its electronic configuration must account for 50 electrons.

The configuration is:

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p²

From this configuration, we see that tin’s outermost shell is the 5th energy level (n = 5).

• In this level, there are 2 electrons in the 5s subshell and 2 electrons in the 5p subshell.

Therefore, tin has a total of 4 valence electrons.