Question

Q6.Choose odd one out and give reason for your choice.
(a) Sodium, Potassium, Calcium, Magnesium, Mercury
(b) Oxygen, Hydrogen, Nitrogen, Gold
(c) Duralumin, Brass, Bronze, Aluminium
(d) Iron, Zinc, Aluminium, Polyethene
(e) Oxygen, Nitrogen, Hydrogen, Chlorine, Helium​

Answer 1

1. calcium (it's a energy )
2. gold (it's a solid one)
3. brass (don't know sorry)
4. polythene(it's a chemical)
5. chlorine (it's a element)

Answer 2

a) Mercury is the odd one out here, all the other elements are normal elements with the penultimate shell completely full and only the ultimate shell incomplete, whereas mercury is a transition element with both penultimate and ultimate shells incomplete, mercury is also a liquid at room temperature.

b) Gold, all the other elements are nonmetals, gold is a metal.

c) Aluminium, aluminium is an element while all others are alloys consisting of one or more elements.

d)Polythene, all the others are elements while polyethene is a compound and a polymer.

e) Helium, helium is a noble gas and is monoatomic while all others are diatomic gases.