A C and D are all correct, Helium and Hydrogen only have a 1s orbital, and helium has 2 protons, while hydrogen has 1, and finally Hydrogen has no neutrons while helium has 2. Helium does not however have 8 valence electrons as the 1s orbital can only hold 2, meaning B is the “correct” (false) answer.
Answer:
A) 3.17 g of Zn
Explanation:
Let's consider the reduction of Zn(II) that occurs in an electrolysis bath.
Zn⁺²(aq) + 2e⁻ → Zn(s)
We can establish the following relations:
- 1 min = 60 s
- 1 A = 1 C/s
- The charge of 1 mole of electrons is 96,468 C (Faraday's constant).
- When 2 moles of electrons circulate, 1 mole of Zn is deposited.
- The molar mass of Zn is 65.38 g/mol
The mass of Zn deposited under these conditions is:

Answer : The mass of the water molecule is 4.5 times greater than the mass of the helium atom.
Explanation :
Assumption : The number of water molecules is equal to the number of helium atoms
Given : The mass of water = 4.5 × The mass of helium ........(1)
The mass of Water = Mass of 1 water molecule × Number of water molecule
The mass of Helium = Mass of 1 helium atom × Number of helium atom
Now these two masses expression put in the equation (1), we get
Mass of 1 water molecule × Number of water molecule = 4.5 × Mass of 1 helium atom × Number of helium atom
As per assumption, the number of water molecules is equal to the number of helium atoms. The relation between the mass of water molecule and the mass of helium atom is,
Mass of water molecule = 4.5 × Mass of helium atom
Therefore, the mass of the water molecule is 4.5 times greater than the mass of the helium atom.
No, it is very unlikely for that to happen.