Write the full ground-state electron configuration for each:

(a) Br (b) Mg (c) Se

Bromine (35) 1s²2s²2p63s²3p⁶3d¹⁰ 4s² 4p⁵

Magnesium (12) 1s2 2s2 2p6 3s²

Selenium (34) 1s²2s²2p63s²3p⁶3d¹⁰ 4s² 4p4

Explanation:

In the SPDF electronic configuration, the S orbital can accommodate maximum of 2 electrons,

The P orbital has maximum of 6 electrons

The D orbital has maximum of 10 electrons

The F orbital has maximum of 14 electrons

Bromine with atomic number 35 belongs to group seven (7) period four (4) it ground state electron configuration is 1s²2s²2p63s²3p⁶3d¹⁰ 4s² 4p⁵

Magnesium with atomic number 12 belongs to group one, period two (2), it ground state electron configuration is 1s2 2s2 2p6 3s²

Selenium has atomic number of 34, it belongs to group six (6), period four (4) it electronic configuration is 1s²2s²2p63s²3p⁶3d¹⁰ 4s² 4p4