7. Which of the following elements is diatomic? Mg
Mn
Sn
F
8. What type of bond to all diatomic molecules have?

7. is F

8. they are all linear and have the length or distance between two atoms

7. the answer is F (Fluorine) ; 8. the answer is covalent

Explanation:

7. Fluorine is one of the 7 diatomic elements.

i wish i could but this one is weird give me abc and i can solve it.

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