it exists as atom or ion but not as sodium molecule. So there is no any sodium sodium bonding between two sodium atoms. Sodium combines with other element or group to form compounds of sodium like sodium chloride ,sodium carbonate ,sodium sulphate etc. Sodium has symbol Na and its atomic no. is 11 .
Strong electron withdrawing groups prevents Friedel Crafts reaction because when a withdrawing group attracts the electrons decrease the availability of the electronic pair and the enough electronic density of it in order to make possible the aromatic electrophilic substitution.
Strong electron donating groups like NH2 doesn’t undergo Friedel Crafts reaction because NH2 is a Lewis base that means an electron donor. Due to Friedel Crafts reaction is an acid base reaction, the AlCl3 will be attacked by the lone pair available from NH2 producing a salt. The same occurs with phenol because the lone pair of electrons available in the OH group so Friedels Crafts doesn’t undergo with benzene attached to the strong electron donating groups NH2 or OH.
J.J. Thomson discovered the electron 1897
NH3 = water (it is actually a water soluble gas)
C6H14 = CCl4 (C6H14 won't mix with water at all)
Na2S = water (Na2S is a salt. Salts dissolve best in water)
Br2 = CCl4, but it will also dissolve in water.
Explanation:
they are located in the neucleus
