Question

Which of the following have the same number of electrons in outermost shell?

• A. Elements with atomic numbers 30, 48, 80
• B. Elements with atomic numbers 14, 15, 16
• C. Elements with atomic numbers 20, 30, 50
• D. Elements with atomic numbers 10, 18, 26

Answer 1

Answer: (A)

Elements with atomic numbers 30, 48, 80

Answer 2

: Element with atomic number, $30 - \lbrack Ar\rbrack 3d^{10}4s^{2}$

Element with atomic number, $48 - \lbrack Kr\rbrack 4d^{10}5s^{2}$

Element with atomic number,$80 - \lbrack Xe\rbrack 4f^{14}5d^{10}6s^{2}$