Answer:
275.3 nm is the wavelength of light required for mercury.
Mercury can not be used to generate electricity from the sun because wavelength at which mercury will emit an electron is smaller than 500 nm.
Explanation:
The wavelength of light required for mercury to emit an electron.
The wavelength of the radiation = 
Energy required fro mercury to to emit an electron = E
Energy required fro mercury to to emit an electron will the energy if the radiation = E' = 
E' = E
To calculate the wavelength of light, we use the equation:
where,
= wavelength of the light
h = Planck's constant = 
c = speed of light =



Wavelength of the sun light in the visible region = 500 nm
500 nm > 275.3 nm

Less energy < more energy
So, this means that mercury can not be used to generate electricity from the sun.
Answer:
CH2
Explanation:
The empirical formula gives the lowest whole number ratio of the elements. In this case, both subscripts can be divided by 20, hence CH2.
Answer:
(3S)-2-chloro-2,3-dimethylpentane is produced exclusively.
Explanation:
Electrophilic addition to (3S)-2,3-dimethylpent-1-ene proceeds through a carbocationic intermediate.
In the first step,
adds onto double bond to produce more stable tertiary carbocation. (protonation)
In the second step,
adds onto carbocation to produce (3S)-2-chloro-2,3-dimethylpentane exclusively.(nucleophilic addition)
So, option (d) is correct.
Nitrogen atomic# 7 7protons, 7electrons, 7 neutrons
Oxygen atomic# 8 8protons, 8electrons, 8neutrons
Phosphorous atomic# 15 15protons, 15 electrons, 15 neutrons
Sulfur atomic#16 16protons, 16electrons, 16 neutrons