Alkali Metal Trends (Part- 2) Video Lecture | Chemistry for JEE Main & Advanced

Ans. Alkali metals are a group of chemical elements that belong to Group 1 of the periodic table. They include elements like lithium, sodium, potassium, and so on. They are called alkali metals because they readily form alkali (basic) compounds when they react with water.

Ans. The general trends in the physical properties of alkali metals include: - Increasing atomic radius: As you move down the group, the atomic radius of alkali metals increases due to the addition of new energy levels. - Decreasing ionization energy: The ionization energy of alkali metals decreases down the group as the outermost electron is farther from the nucleus and experiences less attraction. - Decreasing melting and boiling points: The melting and boiling points of alkali metals decrease down the group due to the weakening metallic bonding as the atomic size increases. - Increasing reactivity: Alkali metals become more reactive as you move down the group. This is because the outermost electron is further away from the nucleus and is easily lost to form positive ions.

Ans. The reactivity of alkali metals with water increases as you move down the group. Lithium, being the first element, is the least reactive and reacts slowly with water. Sodium and potassium, on the other hand, react vigorously with water, producing hydrogen gas and forming alkali (basic) solutions.

Ans. Alkali metals react with halogens (Group 17 elements) to form ionic compounds called metal halides. The reaction is highly exothermic and results in the transfer of electrons from the alkali metal to the halogen. For example, sodium reacts with chlorine to form sodium chloride (table salt) according to the equation: 2Na + Cl2 -> 2NaCl.

Ans. Some common uses of alkali metals are: - Lithium: Used in rechargeable batteries, ceramics, and pharmaceuticals. - Sodium: Used in the manufacture of sodium vapor lamps, soaps, and detergents. - Potassium: Used as a fertilizer in agriculture and in the production of glass. - Rubidium and cesium: Used in atomic clocks and as catalysts in certain chemical reactions.