Answer : The correct option is, [tex]8.988\times 10^{-26}joules[/tex]
Solution :
Formula used :
[tex]E=\frac{h\times c}{\lambda}[/tex]
where,
E = change in energy
h = Planck’s constant = [tex]6.626\times 10^{-34}J/s[/tex]
c = speed of light = [tex]2.998\times 10^{8}m/s[/tex]
[tex]\lambda[/tex] = wavelength = 2.21 m
Now put all the given values in the above formula, we get the energy of an atom.
[tex]E=\frac{(6.626\times 10^{-34}J/s)\times (2.998\times 10^{8}m/s)}{2.21m}[/tex]
[tex]E=8.988\times 10^{-26}joules[/tex]
Therefore, the energy of an atom is, [tex]8.988\times 10^{-26}joules[/tex]
