Define unified atomic mass unit. Calculate its energy equivalent. In an atom X, electrons absorb…
Physics20255 marksNumerical
Figure 10
(a)
Define unified atomic mass unit.
(b)
Calculate its energy equivalent.
(c)
In an atom X, electrons absorb the energy from an external source. This energy “excites” the electrons from a lower-energy level to a higher-energy level around the nucleus of the atom. When electrons return to the ground state, they emit photons.
Figure 10 below is the energy level diagram of atom X with three energy levels, $E_1 = 0\cdot 00\text{ eV}$, $E_2 = 1\cdot 78\text{ eV}$ and $E_3 = 2\cdot 95\text{ eV}$. The ground state is considered $0\text{ eV}$ for reference. The transition of electrons takes place between levels $E_1$ and $E_2$.
(1) What wavelength of radiation is needed to excite the atom to energy level $E_2$ from $E_1$?
(2) Suppose the external source has a power of $100\text{ W}$. What would be the rate of photon emission?
