Which of the following is used as an antiseptic and bleaching agent? MCQ with Answer and Explanation

Explanation:
Cobalt-60 is a radioactive isotope that emits strong gamma radiation. It is widely used in radiotherapy to treat various types of cancers, including blood cancers like leukemia. Iodine-131 is used for thyroid disorders, Carbon-14 for radiocarbon dating, and Sodium-24 for detecting blood clots.

Explanation:
Ionization energy (IE) is the minimum energy needed to remove an electron from an isolated gaseous atom in its ground state to form a cation. A(g) → A⁺(g) + e⁻. Adding an electron is electron affinity. IE is an indicator of reactivity. Metals have low IE, non-metals high IE.

Explanation:
The maximum number of electrons in a shell is given by the formula 2n², where n is the principal quantum number. For the N shell, n = 4. Thus, maximum electrons = 2(4)² = 2(16) = 32. The K, L, M, and N shells hold 2, 8, 18, and 32 electrons respectively.