Question 21 Mark35Cl : number of neutrons 18 : : ${ }^{37} \mathrm{Cl}/latex] : …………….. .Answernumber of neutrons 20View full question & answer→
Question 31 MarkNaH : Valency of $Na : 1:: MgCl _2$ : Valency of MgAnswer2View full question & answer→
Question 51 MarkNitrogen : Valency three : : Fluorine : …………….. .Answervalency oneView full question & answer→