Plzz ans these 2 ques

Plzz ans these 2 ques 6. Find the charge of 27 gm of A13• ion (a) 2.894 x C (b) 2.894* 105 c (C) 2.984 x 106C (d) 2.894 107 C 7. The atomic wt. of two elements (A & B) are 20 and 40 respectively. If x.gm of A contains y atoms. How many atoms present in 2x gm of B. (d) None Of these

We are given that the atomic masses of the two elements A and B are 20 and 40 respectively. Also, we are given that the number of atoms in amount x g of element A is y. Therefore

number of moles of A in x g of A = mass / molar mass =  (x / 20)

number of atoms in x grams of A = number of moles X Avogadro's number 

 = (x / 20) X 6.023 X 10²³ = y  (1)

mass of element B = 2x

number of moles of B in 2x g of B = mass /  molar mass = (2x / 40)

number of atoms in 2x grams of B = number of moles X Avogadro's number 

 = (2x / 40) X 6.023 X 10²³

 =  (x / 20) X 6.023 X 10²³ 

But this is equal to y [from (1)]

Therefore the number of atoms in 2x grams of B is the same as x grams of A that is y.