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Question
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Lithium [At. no. = 3, Mass no. = 7]
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Solution
Structure of atoms:
Z is Atomic Number A is the mass number
Lithium \[\ce{^7_3Li}\]
Z = 3 = p = e
K L
e = 3 = 2, 1
A = p + n
7 = 3 + 3
∴ n = 7 − 3 = 4
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