The number of atoms of sulfur in 2.66 grams of sulfur

5.0 × 10^21 atoms of sulfur

We need to know that 1 mole of an element contains atoms equivalent to the Avogadro's number.

Therefore;

1 mole of an element = 6.022 × 10^23 atoms

Thus, 1 mole of sulfur = 6.022 × 10^23 atoms

But, molar mass of sulfur = 32.065 g/mol

This means;

32.065 g contain 6.022 × 10^23 atoms

Therefore, 2.66 g of Sulfur will contain;

= (2.66 g ÷ 32.065 g/mol) ×  6.022 × 10^23 atoms

= 5.0 × 10^21 atoms

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

indium, and thallium have three electrons i think