Question 18 of 42beginner🔧 ApplyShort Answer3 marks

Write the electronic configuration of the elements having atomic numbers 12, 16 and 18.

Correct Answer

The electronic configuration of an atom is the distribution of its electrons among the various energy shells. For a neutral atom, the number of electrons equals the atomic number.

For the element with atomic number 12, the 12 electrons are distributed as 2 in the K-shell, 8 in the L-shell, and 2 in the M-shell. Thus, its configuration is 2, 8, 2.

For atomic number 16, the 16 electrons distribute as 2 in the K-shell, 8 in the L-shell, and 6 in the M-shell, giving a configuration of 2, 8, 6. For atomic number 18, the 18 electrons distribute as 2 in the K-shell, 8 in the L-shell, and 8 in the M-shell, resulting in a configuration of 2, 8, 8.

Exercise: Pause and Ponder | Q: 15 | (Page 13)
For More Understanding

Explanation

The textbook defines electronic configuration as the distribution of electrons among various shells. Table 8.4 and Fig 8.11 provide the electron distribution for the first eighteen elements, including those with atomic numbers 12, 16, and 18. By filling the K-shell (max 2), L-shell (max 8), and M-shell, we derive the respective configurations.

Solution Steps

  1. Step 1: Identify the number of electrons for each element, which is equal to their atomic numbers (12, 16, and 18).

  2. Step 2: Fill the K-shell with a maximum of 2 electrons.

  3. Step 3: Fill the L-shell with a maximum of 8 electrons.

  4. Step 4: Place the remaining electrons in the M-shell to get the final configurations: 2,8,2; 2,8,6; and 2,8,8.

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