i. Newlands, Moseley, Dobereiner, Mendeleev. ii. Fluorine, Sulphur. Bromine, Iodine. iii. Sodium, Aluminium, Chlorine, Carbon.

Question

Find the odd one out and give reason:

i. Newlands, Moseley, Dobereiner, Mendeleev.

ii. Fluorine, Sulphur. Bromine, Iodine.

iii. Sodium, Aluminium, Chlorine, Carbon.

iv. Nitrogen, Neon, Argon, Helium.

Answer 1

i. Moseley. (Moseley brought out the importance of atomic number, while the other tried to classify the elements on the basis or atomic mass.)

ii. Sulfur. (Others are halogens.)

iii. Carbon. (Carbon belongs to the second row, while the others belong to the third row.)

iv. Nitrogen. (The others are inert gases.)