Question

The total energy of an electron in the first
excited state of hydrogen atom is about
–3.4 eV. Its kinetic energy in this state is
(a) 3.4 eV (b) 6.8 eV
(c) –3.4 eV (d) –6.8 eV

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)

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

$\rule{150}{2}$

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

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 potentialenergies are -6.8 eV respectively .

Hence, correct option is 4.

Answer 2

Answer:

(c) is the correct answer.........