2. In an atom the number electrons in M-shell is equal to the number of electrons in the K and
L Shell. Answer the following questions. (AS4)
a. Which is the outer most shell?
b. How many electrons are there in its outermost shell?
c. What is the atomic number of element?
d. Write the electronic configuration of the element
3. How many elliptical orbits are there in third Bohr’s orbit? (AS1)
4. Following orbital diagram shows the electron configuration of nitrogen atom. Which rule
does not support this? N (Z = 7) (AS1)
5. Which rule is violated in the electronic configuration 1s0
2s2
2p4
?
6. Write the four quantum numbers for the differentiating electron of sodium (Na) atom? (AS1)
7. (i) An electron in an atom has the following set of four quantum numbers to which orbital
does it belong
(ii) Write the four quantum numbers for 1s1
electron.(AS4)
8. Collect the information regarding wave lengths and corresponding frequencies of three primary
colours red, blue and green. (AS4)
9. The wave length of a radio wave is 1.0m. Find its frequency.(AS7)
Multiple choice questions
1) An emission spectrum consists of bright spectral lines on a dark back ground. Which one of
the following does not correspond to the bright spectral lines? [ ]
A) Frequency of emitted radiation B) Wave length of emitted radiation
C) Energy of emitted radiations
D) Velocity of light
2) The maximum number of electrons that can be accommodated in the L – shell of an atom is [ ]
A) 2 B)4 C) 8 D) 16
3) If l = 1 for an atom then the number of orbitals in its sub-shell is [ ]
A) 1 B) 2 C) 3 D) 0
4) The quantum number which explains about size and energy of the orbit or shell is: [ ]
A) n B) l
C) ml
D) ms
Suggested Projects
1. Collect the information of historical development of the atomic theory.
2. Collect the information about the scientists who developed the atomic theories.
