Question

The total energy of the electron in the first excited state of hydrogen is -3.4 eV. What is the kinetic energy of the electron in this state?

Answer 1

$\Large{\underline{\underline{\bf{Solution :}}}}$

Kinetic energy of an object is the energy

that it possess due to its motion.

So, A.T.Q

$\small{\boxed{\sf{Kinetic\,energy= Total \: energy \: of \: electron......(1)}}}$

From the given kinetic energy = -3.4 ev

Substitute the value in equation (1)

$\begin{lgathered}\sf{Kinetic\,energy=-(-3.4 eV)} \\ \\ \sf{Kinetic \: Energy = 3.4 eV}\end{lgathered}$

$\rule{200}{2}$

★ Additional information

$\small{\boxed{\sf{Potential \: energy \: = \: 2 \times \: Total \: energy ......(2)}}}$

From the given total energy = -3.4 V

Substitute the value in equation (2)

$\sf{Potential \: energy = 2 \times \: (-3.4)}$

$\sf{→ -6.8 eV}$

Therefore, Kinetic and potential energy is -6.8 eV respectively .