The primary greenhouse gases are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. So, the correct answer among these options is water vapor, that is considered to be a greenhouse gas.
Answer:
Bonding Order = number of bonding electrons – number of antibonding electrons/2.
So for CO2, there is a total of 16 electrons, 8 of which are antibonding electrons.
So 16 – 8 = 8; divided by 2 = 4. So, 4 is the bonding order of CO2. The molecular structure of CO2 looks like this:
..~-~~..
O=C=O
..~-~~..
Hept for 7, hence the number is seven.
Answer : Electron P has greater energy difference than the Electron N.
Explanation :
Wavelength range of violet light = 400 - 500 nm
Wavelength range of orange light = 600 - 700 nm
The Planck's equation is,

where,
E = energy of light
c = speed of light
= wavelength of light
According to the Planck's equation, wavelength and energy follow inverse relation. As the wavelength increases, energy decreases.
From the given spectrum, the wavelength of violet light is less. We conclude that When electron P gives violet light on transition it means that energy difference between the energy level was high.
From the given spectrum, the wavelength of orange light is more. We conclude that When electron N gives orange light on transition it means that energy difference between the energy level was low.
So, Electron P which gives violet light on transition has greater energy difference than the Electron N.
D. Sublimation is a solid turning directly into a gas