Structure of Atom - Online Test

Answer : Option D
Explaination / Solution:

The Rydberg constant, symbol R∞ for heavy atoms or RH for hydrogen, named after the Swedish physicist Johannes Rydberg, is a physical constant relating to atomic spectra, in the science of spectroscopy.

Answer : Option A
Explaination / Solution:

The Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n = 1 (where n is the principal quantum number), the lowest energy level of the electron.

Answer : Option B
Explaination / Solution:

The Lyman series lies in the ultraviolet, whereas the Paschen, Brackett, and Pfund series lie in the infrared.

Answer : Option C
Explaination / Solution:

The Balmer series or Balmer lines in atomic physics, is the designation of one of a set of six named series describing the spectral line emissions of the hydrogen atom. The Balmer series is calculated using the Balmer formula, an empirical equation discovered by Johann Balmer in 1885 Balmar series lies in visible region of Electromagnetic spectrum.

Answer : Option C
Explaination / Solution:

Isotopes are atoms with the same number of protons but that have a different number of neutrons.

Atomic number of carbon = 6

So number of protons in each isotope = 6

Number of neutrons in 126C= 12-6= 6

Number of neutrons in 136C= 13-6= 7

Number of neutrons in 146C= 14-6= 8

Answer : Option A
Explaination / Solution:

Atomic number of iron (Fe) = 26

So number of protons = 26

Number of protons = number of electrons

But To gain 3+ charge it should loose 3 electron. So number of electrons present = 26-3 = 23

Now atomic mass = 56 (Given).

Number of neutrons = atomic mass - number of protons = 56-26 = 30

Answer : Option C
Explaination / Solution:

atomic number O has atomic number = 8 so number of electrons in O2= 16

while in O+2 there is one unit positive charge so no. of electron =15.

Answer : Option B
Explaination / Solution:

In a atom no. of protons = no. of electrons i.e. P = E while this is not true in case of ions. So number of protons in given atom is 29.

Answer : Option B
Explaination / Solution:

α$\alpha$-particle (He2+) has very high mass compared to proton and electron, therefore very small em$\frac{e}{m}$ ratio. Proton and electron have same charge (magnitude) but former is heavier, hence has smaller value of em$\frac{e}{m}$.

Answer : Option B
Explaination / Solution:

Here l = 3 means the sub shell is f and n = 4 means it is present in 4th orbit. Finally it is a 4f sub shell. The no of orbital in f sub shell =2l+1=2×3+1=7 Each orbital can accommodate 2 electrons. 7×2=14 electrons. Maximum number of electrons in a sub shell with l=3 and n=4 (4f) is 14 electrons.