The stability of the noble gases is due to the fact that they?
have no electron in their outermost shells
have duplet or octet electron configurations
belong to group zero of the periodic table
are volatile in nature
Correct answer is B
Noble / Rare gases belong to group 0 because they have no bonding electrons in their outermost shell to satisfy the octet rule for stability.
How many unpaired electron(s) are there in the nitrogen sub-levels?
3
2
1
none
Correct answer is A
Nitrogen has 7 electrons in all.
Its electronic configuration is = \(1s^22s^22p^3\)
So, it has three unpaired electrons in its p-orbitals.
Note that the p orbital can accommodate a maximum of 6 electrons
decrease in nuclear charge
increase in nuclear charge
decrease in screening effect
increase in screening effect
Correct answer is B
No explanation has been provided for this answer.
4 V cm3
2 V cm3
V/2 cm3
V cm3
Correct answer is B
No explanation has been provided for this answer.
water vapour in the air around the bottle gains some energy from the bottle
temperature of the milk drops as it loses heat into the surroundings
saturated vapour pressure of the milk is equal to the atmospheric pressure
water vapour in the air around the bottle loses some of its energy to the bottle
Correct answer is D
When a cold milk bottle is taken out from the refrigerator, the water vapor in the air around the bottle comes in contact with the cold surface of the bottle and gets condensed.