The S-block Elements

i. Zn + 2NaOH → Na? ZnO? + H?
ii. 4Au + 8NaCN + O? + 2H? O → 4Na [Au (CN)? ]+ 4NaOH
iii. Cu + 4HNO? → Cu (NO? )? + 2NO? + 2H? O
(conc.)

Beo & Be (OH)₂ are amphoteric in nature, because they react with both acid and base

(a) Li → used in bearings for motor engine.
(b) Na → used as coolant in fast breader nuclear reactor.
(c) K → used as absorbent of CO?
(d) Cs → used in photoelectric call.

The para-magnetism of solution of alkali metals in liquid ammonia and its deep blue color is due to ammoniated electrons. Which absorb energy in visible region of light.

Ca plays important role in Neuromuscular function and interneuronal transmission. The daily requirement of Mg and Ca in the human body is estimated to be 200 – 300mg. All enzymes that utilise ATP in phosphate transfer require Mg as the cofactor. The bone in human body is NOT an inert and unchanging substance.

BeCl? is covalent and soluble in a organic solvent

Tritium is radioactive and emits low energy β? particles (? e? )

No. of atoms in Hexagonal primitive unit cell = 6
No. of Tetrahedral voids = 2 * No. of atoms per unit cell
= 2 * 6 = 12
No. of Octahedral voids = No. of atoms per unit cell = 6

Li is used in making batteries, liquid Na is a coolant in nuclear reactors. Cs is used in photoelectric cells and KOH as a base is used to absorb acidic oxides like CO?

The oxidation state of K in KO? is (+1).