Number of moles = 0.0688 moles of NaoH
volume = 0.250 L
Molarity = moles of solute / volume ( L )
M = 0.0688 / 0.250
M = 0.28 M
Answer B
The most suitable answer is C becuase they would gain two elctrons to atain that stable OCTET thus becoming a anion with a charge of -2 and by virtue oxidation states of -2. There is however an exception with oxygen in two cases. But I still remain that the best answer would be C
Answer:

Explanation:
Ionic bond is a bond between metals and non-metals with strong forces of attraction between charged ions.
Answer:
V = 44.85 L
Explanation:
Given data:
Volume of H₂ = ?
Number of moles of H₂ = 2.0 mol
Given temperature = 273.15 K
Given pressure = 1 atm
Solution:
Formula:
PV = nRT
P = Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
By putting values,
1 atm × V = 2.0 mol × 0.0821 atm.L/ mol.K × 273.15 K
V = 44.85 atm.L / 1 atm
V = 44.85 L