Alkali metals show similarity in their chemical behaviour due to similar valence shell electronic configuration,

Caesium hydroxide (CsOH) is a chemical compound consisting of an ion of caesium and a hydroxide ion. It is a strong base (pK_b = -1.76), much like the other alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.

Carnallite is an evaporite mineral, a hydrated potassium magnesium chloride with formula: KMgCl₃·6(H₂O).

The solutions of metal in liquid ammonia are strong reducing agents due to solvated electrons.

When crystals of sodium chloride are thrown in fire, water comes out of them with a cracking sound.

Traditionally, flint glasses are lead glasses containing around 4-60% lead oxide.

The diamond burns in air at 900 °C to give CO2.

Sulphur trioxide (SO₃) is prepared by heating concentrated sulphuric acid (H₂SO₄), with a large excess of phosphorus pentoxide (P2O5).

H₂SO₄ + P₂O₅ ^_______SO₃ + 2HPO3

n order for PCl₅ to be formed, there must be five bonds, and to form five bonds, phosphorus must have five unpaired valence electrons. Phosphorus and nitrogen both have five valence electrons.

In order to have five unpaired electrons in P, we can imagine an electron being promoted from the 3s to the 3d sub-level. This will give 5 unpaired electrons, and the ability to form PCl₅. We can also relate this to the use of the d orbitals in phosphorus with sp³d hybridisation.

But for nitrogen, there are no 2d orbitals to promote a 2s electron into and no way to come up with five unpaired electrons. Therefore, NCl₅ does not exist.

As the positive charge decreases, the bond between nitrogen and oxygen becomes stronger. So, the correct order of the bond energies is NO⁺ > NO > NO^-.

The term inert pair effect is often used in relation to the increasing stability of oxidation states that are 2 less than the group valency for the heavier elements of groups 13, 14, 15 and 16. It is not a characteristic of the actinide series of elements.

The tendency of the transition metals to form complex ions is due to:

(a) Small size of the metals ion

(b) Large ionic or nuclear charge

(c) Available d- orbitals

(d) Low basicity of the metal ions

(e) Availability of various oxidation state

(f) High lewis acid nature of electron pair accepting tendency of the metal ion.

Development of a photographic plate involves the use of a reducing agent.

In the silver plating of copper, K[Ag(CN)₂] is used instead of AgNO₃. This is because of less availability of Ag⁺ ions as Cu cannot displace Ag from [Ag(CN)₂]^- ion