C unbalanced force is occuring
Answer is 3
s -1
p - 3
d - 5
f - 7
Answer: an increase in the concentration of
in aqueous solutions and is capable of donating one or more 
Explanation:
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions
when dissolved in water and an acid is defined as a substance which donates hydrogen ions
in water.
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
Thus According to the Arrhenius concept, an acid is a substance that causes an increase in the concentration of
in aqueous solutions and is capable of donating one or more 
Use the ideal gas law:
PV = nRT
so, T = PV / nR
n=0.5
V= 120 dm^3 = 120 L (1 dm^3 = 1 L)
R = 1/12
P = 15,000 Pa = 0.147 atm (1 pa = 9.86 10^{-6} )
Put the values:
T = PV / nR
T = (0.147) (120) / (0.5) (1/12)
T= 426 K