Answer:
Maybe they both have valence electrons and can be used in chemical reactions. I could be wrong, I don't have any exact answers.
Explanation:
The answer is (3)Ne. Usually, the elements belongs to group 18 all have completely filled valence electron shell. Among the four elements carbon, vanadium, neon and antimony, only neon belongs to group 18.
Number of moles is defined as the ratio of given mass in g to the molar mass.
The mathematical formula is:
Number of moles =
(1)
Number of zinc atoms is equal to
, by Avogadro number, number of moles can be calculated.
As, 1 mol=
atoms, hence,

= 0.2822 mol
Now, from formula (1), calculate mass in g (molar mass of zinc = 65.4 g/mol)
0.2822 mol =
mass in g = 
= 18.45588 g
Thus, by rounding off the above number, it will come near about 19 g approximately.
Hence, option (C) is the correct answer.
Precipitation
100°C
When 1 mol of water vapor at 100°C condenses to liquid water at 100°C, 40.7 kJ of heat are released into the surroundings.
Answer:
2.01
Explanation:
The effusion is the passage of the molecules by a small hole by a difference of pressure. By Graham's Law, the rate of the effusion is inversely proportional to the square of the molar mass of the compound. Thus,
rateHF/rateHBr = √MHBr /√MHF
MHBr = 81 g/mol
MHF = 20 g/mol
rateHF/rateHBr = √81/√20
rateHF/rateHBr = 2.01