The structure of an atom is an atom consists of a nucleus and a number of electrons present around the nucleus. All the three charges have a mass value and the mass of protons and neutrons together gives the mass of the nucleus i.e. the atomic mass of the element. The protons and neutrons make up the nucleus of the atom, which is surrounded by the electrons belonging to the atom. The atomic number of an element describes the total number of protons in its nucleus. Let's know more about Atomic Structure.
1. Neutron is a fundamental particle which have:-
A. +1 unit charge and 1 unit mass
B. No charge and 1 unit mass
C. Have no charge and mass
D. Have -1 unit charge and 1 unit mass
2. Na+ is isoelectronic with:-
A. Li+
B. Mg+²
C. Ca+²
D. Ba+²
3. What is the number of unpaired electrons in 1s², 2s²2p⁴?
A. 4
B. 2
C. 0
D. 1
4. Principal quantum number represents:-
A. Shape of orbital
B. Distance between nucleus and electron
C. No. of electron in one shell
D. No. of orbitals in one shell
5. Unpaired electron present in Cr+³...
A. 3
B. 1
C. 2
D. 5
6. Which of the following pair is isoelectronic?
A. Ca, Ar
B. Mg, Na+
C. Ag, Sn
D. Ar, Clˉ
7. Which of the following set of quantum numbers (n,l,m,s) is not correct:-
A. 3, 1, 0, -1/2
B. 3, 2, 1, +1/2
C. 3, 1, 2, -1/2
D. 3, 2, 0, +1/2
8. If the Hydrogen atom is excited by giving 8.4ev energy, then no. of emitted, spectrum line will be:-
A. None
B. Two
C. Three
D. Four
9. No. of unpaired electron present in an inert gas...
A. 5
B. 3
C. 0
D. 2
10. Which of the following is incorrect for n=5 and m=3?
A. l=4
B. l=3
C. l=0, 1, 2, 3
D. s= +1/2
11. An element M has 25 protons. The no. of electrons in its M+² cation will be...
A. 25
B. 24
C. 23
D. 22
12. Maximum frequency of emission is obtained for the transition...
A. N=2 to N=1
B. N=6 to N=2
C. N=1 to N=2
D. N=2 to N=6
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