Just 2 valence electrons.
Hydrogen already has one to start with, as well. With the exception of hydrogen and helium, all other atoms need 8 valence e-
Answer : q = 6020 J, w = -6020 J, Δe = 0
Solution : Given,
Molar heat of fusion of ice = 6020 J/mole
Number of moles = 1 mole
Pressure = 1 atm
Molar heat of fusion : It is defined as the amount of energy required to melt 1 mole of a substance at its melting point. There is no temperature change.
The relation between heat and molar heat of fusion is,
(in terms of mass)
or,
(in terms of moles)
Now we have to calculate the value of q.

When temperature is constant then the system behaves isothermally and Δe is a temperature dependent variable.
So, the value of 
Now we have to calculate the value of w.
Formula used : 
where, q is heat required, w is work done and
is internal energy.
Now put all the given values in above formula, we get

w = -6020 J
Therefore, q = 6020 J, w = -6020 J, Δe = 0
<span>
The conditions in tornado alley are more favorable. In the summer, the plains of middle US get increasingly hot which in turn, cause updrafts as well as thunderstorms. When hot air becomes unstable and rises it meets cooler air above the thunderclouds, which causes tornadoes.</span>
A cation (+) will be smaller than its neutral atom, while anion (-) will be larger than its neutral atom.
Answer:
Option (D)
Explanation:
The super-heating is usually defined as a phenomenon where a certain amount of energy is needed to raise the temperature of the water vapor beyond its normal saturation point. This is also known as the boiling delay.
The super-heat can be mathematically written as:
Super-heat = Current temperature - Boiling point of the liquid.
Thus, super-heat refers to the amount of energy that is required to increase the temperature of vapor beyond its point of saturation.
This super-heat is essential as it helps in preventing the damages of machines like air conditioner, fridge and also helps in their soft running.
Hence, the correct answer is option (D).