alkaly mystals hydroxides are basic in nature. Attrati earth metali Cexcept 8p), amp. metal. • hydroxides ver basic in nature • oxides are prisent. in earth's crust Es becaus 4 beause: khas empty & orbital ccupies be experimentally has bigger density. more space Velwere t density & 3) photo electric effect:-?? Due to low It, S block elements shows photoelectric effers egils. Melting point: nuttalle bouding mettalic bouding & no. of free e 5) Plame test: sblock elements and its calt giver characteric colour to the flame cli crimson red beno dos Tue to cow Golden yellow LK lilac(violet) & Vals visit W why kycoz cant be prepared by cobring Solvay's process? soluble Aus Because KHIO3 is semble so we it to get k₂ 103. cant heat From the fig: We can cheerve that: properties of Na2CO3 efflorescence: Na₂ 103 101120 looses 9 H₂0 of 10 H20 molecule. Thus it looser weight on exposure to ais. This prouss is called efflorescence! USES I of lithium und to make useful alloys, for 1 (11) with dead to make white metal bearing. for motor engines, with aluminium to make rischaft parts, and with magnesium to make armour plates. It is used in thermonuclear reactions and also to make electro chemical cells. 2. of sodium: (Na) It is used to make NalPb alloy needed to maki PbEty and PbMe 4. These organdead compend were earlier used as auti-knock additives to petrol, but nowadays velicals use lead fres. petrol -liquid sodium metal is used as a coolant in fast breedes nuclear reactors. 3. of Pottasium: (k) Pottasim has vital role in biological systion. Petlatinum chloride is used as a fertilizer. Petlove byproxide is used in the manufacture of soft co It's also need as an excellent absorbent. of carbon dioxide Ar of Caesium (Cs) it is used in devising photoelectric cells. 5. of sodium Carbonate (Na,Ca) 1. It's used in water softening, laundering and cleaning 2. It's used in the manufacture of glass, borax and caustic soda 3. It's used in paper, paints and textile Industries 4 It's ump. laboratory reagent both in qualitative and quantitative analysis. 6 of sodium chloride (Nace) I und commen Hable salt for domestic purpose 2. It's used for the preparation of Naz02, Naom and Na, c03 7. of Sodium hydroxide (NaOH) 1- used in manufacture silk and no. of chemicals. soap, paper, artificial In petroleuen refining 4. In the textile industries. for mercerising cotton fabrics . In the purification of bauxite