Can you show me the answer and explain?

C

Explanation:

looking at a periodic table X is fluorine and Y is potassium

Fluorine is in group 7 and forms a 1- charge (which gains electrons) and potassium is in group 1 and forms a 1+ charge (which loses electrons)

Fluorine (X) has an electronic structure of 2,7 and needs to gain an electron from Potassium (Y) to have a full outer shell and potassium has an electronic structure of 2,8,8,1 so needs to lose an electron to have a full outer shell as well. This means that the electron that potassium (Y) has lost is given away to fluorine (X), so both elements become stable.

This is known as ionic bonding where metals (like potassium) lose electrons and non-metals (like fluorine) gain electrons to become more stable, forming ions

Any further clarification let me know

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2

it's c (engineer's do their work with mechanical stuff not on any living being)