CBSE
1 mole of photon, each of frequency 2500 s-1, would have approximately a total energy of
10 erg
1 J
1 eV
1 MeV
The orbital angular momentum of an electron in 2s orbital is
zero
In Sommerfeld's modification of Bohr's theory, the trajectory of an electron in a hydrogen atom is
a perfect ellipse
a closed ellipse-like curve, narrower at the perihelion position and flatter at the aphelion position
a closed loop on spherical surface
a rosette
A radioactive atom emits two particles and one particle successively. The number of neutrons in the nucleus of the product will be:
X - 4 - Y
X - Y - 5
X - Y - 3
X - Y - 6
are respectively
4,1
3,7
8,1
4,7
The radius of hydrogen atom is 0.53 Å. The radius of 3Li2+ is of:
1.27 Å
0.17 Å
0.57 Å
0.99 Å
Which of the following expressions gives the de-Broglie relationship?
For the Paschen series the values of n1 and n2 in the expression
n1= 1, n2 = 2, 3, 4, ...
n1= 2, n2 = 3, 4, 5,...
n1= 3, n2 = 4,5,6,...
n1= 4, n2 = 5,6,7,...
If a species has 16 protons, 18 electrons and 16 neutrons, find the species and its charge.
S1-
Si2-
P3-
S2-
The number of electron and neturons of an element is 18 and 20 respectively. Its mass number is
2
17
37
38