`color{green}( ★)` The alkaline earth metals are less reactive than the alkali metals. The reactivity of these elements increases on going down the group.
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐚𝐢𝐫 𝐚𝐧𝐝 𝐰𝐚𝐭𝐞𝐫 :")`
`color{green}( ★)` Beryllium and magnesium are kinetically inert to oxygen and water because of the formation of an oxide film on their surface.
`color{green}( ★)` However, powdered beryllium burns brilliantly on ignition in air to give `color{red}(BeO)` and `color{red}(Be_3N_2)`.
`color{green}( ★)` Magnesium is more electropositive and burns with dazzling brilliance in air to give `color{red}(MgO)` and `color{red}(Mg_3N_2)`.
`color{green}( ★)` Calcium, strontium and barium are readily attacked by air to form the oxide and nitride.
`color{green}( ★)` They also react with water with increasing vigour even in cold to form hydroxides.
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐭𝐡𝐞 𝐡𝐚𝐥𝐨𝐠𝐞𝐧𝐬 :")`
`color{green}( ★)` All the alkaline earth metals combine with halogen at elevated temperatures forming their halides.
`color{red}(M+X_2 → MX_2 ( X = F , Cl , Br , I))`
`color{green}( ★)` Thermal decomposition of `color{red}((NH_4)_2BeF_4)` is the best route for the preparation of `color{red}(BeF_2)`, and
`color{red}(BeCl_2)` is conveniently made from the oxide.
`color{red}(BeO + C + Cl_2 overset(600-800K)⇌ BeCl_2 + CO)`
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐡𝐲𝐝𝐫𝐨𝐠𝐞𝐧 :")`
`color{green}( ★)` All the elements except beryllium combine with hydrogen upon heating to form their hydrides,
`color{red}(MH_2).`
`color{green}( ★)` `color{red}(BeH_2)` however, can be prepared by the reaction of `color{red}(BeCl_2)` with `color{red}(LiAlH_4)`
`color{red}(2BeCl_2 + LiAlH_4 → 2 BeH_2 + LiCl + AlCl_3)`
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐚𝐜𝐢𝐝𝐬 :")`
`color{green}( ★)` The alkaline earth metals readily react with acids liberating dihydrogen.
`color{red}(M + 2HCl → MCl_2 + H_2)`
`color{green}( ★ \ \ "𝐑𝐞𝐝𝐮𝐜𝐢𝐧𝐠 𝐧𝐚𝐭𝐮𝐫𝐞 :")`
`color{green}( ★)` Like alkali metals, the alkaline earth metals are strong reducing agents.
`color{green}( ★)` This is indicated by large negative values of their reduction potentials (Table 10.2).
`color{green}( ★)` However their reducing power is less than those of their corresponding alkali metals.
`color{green}( ★)` Beryllium has less negative value compared to other alkaline earth metals.
`color{green}( ★)` However, its reducing nature is due to large hydration energy associated with the small size of `color{red}(Be^(2+))` ion and relatively large value of the atomization enthalpy of the metal.
`color{green}( ★ \ \ "𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬 𝐢𝐧 𝐥𝐢𝐪𝐮𝐢𝐝 𝐚𝐦𝐦𝐨𝐧𝐢𝐚 :")`
`color{green}( ★)` Like alkali metals, the alkaline earth metals dissolve in liquid ammonia to give deep blue black solutions forming ammoniated ions.
`color{red}(M + (x+y) NH_3 → [ M (NH_3)_X]^(2+) + 2 [ e (NH_3)_Y]^(-))`
`color{green}( ★)` From these solutions, the ammoniates, `color{red}([M(NH_3)_6]^(2+))` can be recovered.
`color{green}( ★ \ \ "𝐔𝐬𝐞𝐬 :")`
`color{green}( • )` Beryllium is used in the manufacture of alloys.
`color{green}( •)` Copper-beryllium alloys are used in the preparation of high strength springs.
`color{green}( • )` Metallic beryllium is used for making windows of X-ray tubes.
`color{green}( •)` Magnesium forms alloys with aluminium, zinc, manganese and tin.
`color{green}(•)` Magnesium-aluminium alloys being light in mass are used in air-craft construction.
`color{green}( •)` Magnesium (powder and ribbon) is used in flash powders and bulbs, incendiary bombs and signals.
`color{green}( •)` A suspension of magnesium hydroxide in water (called milk of magnesia) is used as antacid in medicine.
`color{green}( •)` Magnesium carbonate is an ingredient of toothpaste.
`color{green}( •)` Calcium is used in the extraction of metals from oxides which are difficult to reduce with carbon.
`color{green}( •)` Calcium and barium metals, owing to their reactivity with oxygen and nitrogen at elevated temperatures, have often been used to remove air from vacuum tubes.
`color{green}( •)` Radium salts are used in radiotherapy, for example, in the treatment of cancer.
`color{green}( ★)` The alkaline earth metals are less reactive than the alkali metals. The reactivity of these elements increases on going down the group.
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐚𝐢𝐫 𝐚𝐧𝐝 𝐰𝐚𝐭𝐞𝐫 :")`
`color{green}( ★)` Beryllium and magnesium are kinetically inert to oxygen and water because of the formation of an oxide film on their surface.
`color{green}( ★)` However, powdered beryllium burns brilliantly on ignition in air to give `color{red}(BeO)` and `color{red}(Be_3N_2)`.
`color{green}( ★)` Magnesium is more electropositive and burns with dazzling brilliance in air to give `color{red}(MgO)` and `color{red}(Mg_3N_2)`.
`color{green}( ★)` Calcium, strontium and barium are readily attacked by air to form the oxide and nitride.
`color{green}( ★)` They also react with water with increasing vigour even in cold to form hydroxides.
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐭𝐡𝐞 𝐡𝐚𝐥𝐨𝐠𝐞𝐧𝐬 :")`
`color{green}( ★)` All the alkaline earth metals combine with halogen at elevated temperatures forming their halides.
`color{red}(M+X_2 → MX_2 ( X = F , Cl , Br , I))`
`color{green}( ★)` Thermal decomposition of `color{red}((NH_4)_2BeF_4)` is the best route for the preparation of `color{red}(BeF_2)`, and
`color{red}(BeCl_2)` is conveniently made from the oxide.
`color{red}(BeO + C + Cl_2 overset(600-800K)⇌ BeCl_2 + CO)`
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐡𝐲𝐝𝐫𝐨𝐠𝐞𝐧 :")`
`color{green}( ★)` All the elements except beryllium combine with hydrogen upon heating to form their hydrides,
`color{red}(MH_2).`
`color{green}( ★)` `color{red}(BeH_2)` however, can be prepared by the reaction of `color{red}(BeCl_2)` with `color{red}(LiAlH_4)`
`color{red}(2BeCl_2 + LiAlH_4 → 2 BeH_2 + LiCl + AlCl_3)`
`color{green}( ★ \ \ "𝐑𝐞𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨𝐰𝐚𝐫𝐝𝐬 𝐚𝐜𝐢𝐝𝐬 :")`
`color{green}( ★)` The alkaline earth metals readily react with acids liberating dihydrogen.
`color{red}(M + 2HCl → MCl_2 + H_2)`
`color{green}( ★ \ \ "𝐑𝐞𝐝𝐮𝐜𝐢𝐧𝐠 𝐧𝐚𝐭𝐮𝐫𝐞 :")`
`color{green}( ★)` Like alkali metals, the alkaline earth metals are strong reducing agents.
`color{green}( ★)` This is indicated by large negative values of their reduction potentials (Table 10.2).
`color{green}( ★)` However their reducing power is less than those of their corresponding alkali metals.
`color{green}( ★)` Beryllium has less negative value compared to other alkaline earth metals.
`color{green}( ★)` However, its reducing nature is due to large hydration energy associated with the small size of `color{red}(Be^(2+))` ion and relatively large value of the atomization enthalpy of the metal.
`color{green}( ★ \ \ "𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬 𝐢𝐧 𝐥𝐢𝐪𝐮𝐢𝐝 𝐚𝐦𝐦𝐨𝐧𝐢𝐚 :")`
`color{green}( ★)` Like alkali metals, the alkaline earth metals dissolve in liquid ammonia to give deep blue black solutions forming ammoniated ions.
`color{red}(M + (x+y) NH_3 → [ M (NH_3)_X]^(2+) + 2 [ e (NH_3)_Y]^(-))`
`color{green}( ★)` From these solutions, the ammoniates, `color{red}([M(NH_3)_6]^(2+))` can be recovered.
`color{green}( ★ \ \ "𝐔𝐬𝐞𝐬 :")`
`color{green}( • )` Beryllium is used in the manufacture of alloys.
`color{green}( •)` Copper-beryllium alloys are used in the preparation of high strength springs.
`color{green}( • )` Metallic beryllium is used for making windows of X-ray tubes.
`color{green}( •)` Magnesium forms alloys with aluminium, zinc, manganese and tin.
`color{green}(•)` Magnesium-aluminium alloys being light in mass are used in air-craft construction.
`color{green}( •)` Magnesium (powder and ribbon) is used in flash powders and bulbs, incendiary bombs and signals.
`color{green}( •)` A suspension of magnesium hydroxide in water (called milk of magnesia) is used as antacid in medicine.
`color{green}( •)` Magnesium carbonate is an ingredient of toothpaste.
`color{green}( •)` Calcium is used in the extraction of metals from oxides which are difficult to reduce with carbon.
`color{green}( •)` Calcium and barium metals, owing to their reactivity with oxygen and nitrogen at elevated temperatures, have often been used to remove air from vacuum tubes.
`color{green}( •)` Radium salts are used in radiotherapy, for example, in the treatment of cancer.