An atom has mass number 40 and atomic number 20.
(i) How many electrons are revolving around the nucleus?
(ii) How many electron shells are there in the atom?
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An atom has mass number 40 and atomic number 20.
(i) How many electrons are revolving around the nucleus?
(ii) How many electron shells are there in the atom?
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Verified answer
Hey there !!Atomic number = Z = 20
We know that
Number of protons = Atomic number
Hence , Number of protons = 20
Mass number = 40
1) How many electrons are revolving around the nucleus?
ans :-
The number of electrons in an atom is equal to the no: of protons.
Hence , no: of electrons = 20
2)How many electron shells are there in the atom?
Ans:-
No: of electrons = 20
Electronic configuration = 2 , 8 , 8 , 2
Hence , there are 4 electron shell :-
K shell [ 2 electrons]
L shell [ 8 electrons ]
M shell [ 8 electrons ]
N shell [ 2 electrons ]
1.total 20electrons are revolving around nucleus.
2.k shell(2)L shell(8),M shell(18).so 4shells.