Question

1st group Elements are Also called as ​

Answer 1

• 1st group Elements are Also called as $\sf\underline \pink {Alkali \: Metals}$

Know More :-

• Alkali Metals are very soft or Brittle as the metallic bonding between the atoms is weak.

• They have relatively low Boiling points compared to other Elements in the Periodic table as there Latice Energy is very low.

• Alkali Metals are Generally Silvery white in colour.

• They are highly reactive and cannot be stored in Atmospheric conditions, Therefore they are stored in kerosene (Before they are wrapped in Paraffin wax).

• Lithium is the lightest metal among all the elements having a Density of 0.534 g/cm³ (It floats on water).

↪ Reaction with Oxygen:-

• Alkali Metals react with oxygen to form Metal oxides which are basic in Nature.

• Lithium Reacts with Oxygen to Form Lithium Monoxide (Li₂O).

• Sodium reacts with oxygen to form Sodium Peroxide (Na₂O₂).

• Remaining Metals Combin with Oxygen to Form respective Super oxides (MO₂).

↪ Reaction with Water:-

Reaction:-

$\purple{\bold{\sf 2M + 2H_2 O \xrightarrow{} 2M^+ + 2OH^- + H_2}}$

(M = An alkali Metal)

• The Tendency to Form oxides Depends upon their Electrode Potential.

• This reaction usually liberates Hydrogen gas.

• Some Alkali Metals react so vigorously (Sodium & Potassium) that they catch fire immediately.

↪ Reaction with Dihydrogen:-

Reaction:-

$\green{\bold{\sf 2M + H_2 \xrightarrow{Heat} 2M^+ H^-}}$

(M = An Alkali metal)

• Ist group Elements or Alkali Metals react with Hydrogen at 673 K (or) 400°C to Form Metal Hydrides.

• These Hydrides are Crystalline & Ionic in Nature.

Answer 2

Answer:

1st group elements are also called as

Alkali Metals

➡ Alkali Metals are very soft or Brittle as the metallic bonding between the atoms is weak.

➡ They have relatively low Boiling points compared to other Elements in the Periodic table as there latice energy is very low.

➡ Alkali Metals are Generally Silvery white in colour.

➡ They are highly reactive and cannot be stored in Atmospheric conditions, Therefore they are stored in kerosene (Before they are wrapped in Paraffin wax).

➡ Lithium is the lightest metal among all the elements having a Density of 0.534 g/cm³ (It floats on water)