The picture of correct answer is attached it is the second one from the left since it has 5 electrons in outermost shell so it can share 3 electrons to complete the octet rule, while first one contains only one electron in outermost shell so it easier to be lost, third one has 8 electrons so it has complete valence shell and last one with only two electrons in outermost shell so it is easier to lose these two electrons.
from 5 to 7 electrons on outermost shell can form covalent bond
Answer:
The molar mass of the metal is 54.9 g/mol.
Explanation:
When we work with gases collected over water, the total pressure (atmospheric pressure) is equal to the sum of the vapor pressure of water and the pressure of the gas.
Patm = Pwater + PH₂
PH₂ = Patm - Pwater = 1.0079 bar - 0.03167 bar = 0.9762 bar
The pressure of H₂ is:

The absolute temperature is:
K = °C + 273 = 25°C + 273 = 298 K
We can calculate the moles of H₂ using the ideal gas equation.

Let's consider the following balanced equation.
M(s) + H₂SO₄(aq) ⟶ MSO₄(aq) + H₂(g)
The molar ratio of M:H₂ is 1:1. So, 9.81 × 10⁻³ moles of M reacted. The molar mass of the metal is:
