Magnesium is essential for many biological processes, including muscle contraction. Class 9

Magnesium is essential for many biological processes, including muscle contraction. Class 9

Question 1.

Magnesium is essential for many biological processes, including muscle contraction. For an atom of magnesium with a mass number of 24 and atomic number 12, determine the number of (i) protons, (ii) neutrons, (iii) electrons, and also illustrate the arrangement of electrons in a magnesium atom. Class 9

Answer:

Mass number (A) = 24, Atomic number (Z) = 12.

(i) Number of protons = Atomic number = 12.

(ii Number of neutrons = Mass number - Atomic number = 24 - 12 = 12.

(iii) Number of electrons = Number of protons (atom is neutral) = 12.

Arrangement of electrons in Magnesium (Electronic Configuration):

1. K-shell (n = 1): 2 electrons (maximum = 2, filled first)
2. L-shell (n = 2): 8 electrons (maximum = 8, filled next)
3. M-shell (n = 3): 2 electrons (remaining electrons)
4. Electronic configuration: 2, 8, 2