Question

How many valence electrons does zinc have?

Answer 1

Hint: The atoms have different shells, which are denoted by K, L, M, N, and so on. The number of electrons in an atom determines how the atom's electrons are organized into shells; the valence shell is the last shell of the atom, and the electrons in that shell are valence electrons. The atomic number of zinc is 30 so, 30 electrons are there in the atom.

Complete answer:
The periodic table is a list of elements arranged in ascending order of their number of electrons, which are then filled in orbits according to their increasing energies. The basic energy of the shell is denoted by K, L, M, N, and other letters of the atoms. The shell K denotes 1, the shell L denotes 2, the shell M denotes 3, and the shell N denotes 4. Each shell has distinct subshells, such as s, p, d, f, and so on.
The number of electrons in an atom is distributed in shells, and the valence shell is the last shell of the atom, with valence electrons as the electrons in that shell. These valence electrons are responsible for bond-forming. Since the valence electron determines the element's block, if the last electron reaches the s-subshell, the product belongs to the s-block.
The atomic number zinc is 30 so, its electronic configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^2$. The last shell is 4 and the electrons in the last shell are 2. So, the valence electrons of zinc are 2.

Note:
The K shell has one sub-shell (s), the L shell has two (s, p), the M shell has three (s, p, d), and the N shell has four (s, p, d, f). The cumulative number of electrons in the last shell, and all sub-shells, is referred to as valence electrons.