Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one: (i) forms an anion (ii) forms a cation

 Question:

Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one:

 (i) forms an anion

 (ii) forms a cation

Solution:

(i)                     Y

(ii)                   Z

Explanation:

Write the electronic configuration of the elements given.

X (Atomic number-6) - 2,4

Y (Atomic number- 9) - 2,7

Z (Atomic number- 12) - 2, 8, 2

X can gain 4 electrons or lose 4 electrons.

Y will accept 1 electron to have 8 electrons in its valence shell.

Z will lose 2 electrons to attain octet(8 electrons) in the last shell.

(i) Anion means negative ion. Since Y will gain electrons, it will become negatively charged and form an anion.

(ii) Cation means positive ion. Since Z will lose electrons, it will become positively charged and form a cation.