MEDIUM
JEE Main/Advance
IMPORTANT
Earn 100

Why is the cathode ray tube experiment not conducted at atmospheric pressure?

Important Questions on Structure of Atom

MEDIUM
JEE Main/Advance
IMPORTANT
The threshold frequency for the ejection of electrons from potassium metal is 5.3×1014 s-1. Will the photon of a radiation having energy 3.3×10-13 J exhibit the photoelectric effect? h=6.6×10-34 Js
MEDIUM
JEE Main/Advance
IMPORTANT
If the work function w of an arbitrary metal is 3.1 eV, find its threshold wavelength and the maximum kinetic energy of the electron emitted when the radiation of 300 nm strikes the metal surface. (Take hc=12400 eV A).
MEDIUM
JEE Main/Advance
IMPORTANT
Calculate the speed of an electron in the ground state of He+ ion. What fraction of speed of light is this value? How long does it take for the electron to complete one revolution around the nucleus. How many times does the electron travel around the nucleus in one second?
MEDIUM
JEE Main/Advance
IMPORTANT

The energy levels of hypothetical one electron atom are shown below.
0 eV_____n=
-0.50 eV_____n=5
-1.45 eV_____n=4
-3.08 eV_____n=3
-5.3 eV_____n=2
-15.6 eV_____n=1
(a) Find the ionisation potential of atom?
(b) Find the short wavelength limit of the series terminating at n=2?
(c) Find the wave number of photon emitted for the transition made by the electron from third orbit to first orbit?
 

HARD
JEE Main/Advance
IMPORTANT
Calculate the energy emitted when electrons of 1.0 g atom of hydrogen undergo transition giving the spectral lines of lowest energy in the visible region of its atomic spectra.RH=1.1×107 m-1, c=3×108 m sec-1 and h=6.62×10-34 J sec
HARD
JEE Main/Advance
IMPORTANT

Calculate the energy required to excite one litre of hydrogen gas at 1 atm and 298 K to the first excited state of atomic hydrogen. The energy for the dissociation of H-H bond is 436 kJ mol-1

HARD
JEE Main/Advance
IMPORTANT

The wave function of 3s electron is given by  ψ3s=1813π1a03/227-18ra0+2ra02e-r/3a0

It has a node at r=r0. Find the relations between r0 and a0.

MEDIUM
JEE Main/Advance
IMPORTANT
The value of Planck's constant is 6.3×10-34 Js. The velocity of light is 3×108 m sec-1. Which value is closest to the wavelength of a quantum of light with frequency of 8×1015 sec-1?