How you rank the following items in order of complexity. Carbon atom
Methane molecule (CH4)
Graphite
Diamond
Using what you understand about atomic and molecular structure explain why you ranked them the way you did.

lowest to Highest

Carbon atom  

Methane molecule (CH4)  

Graphite  

Diamond

Explanation:

A carbon atom would be the lowest complexity on this list, that is because it is a lone molecule with no other bonding between other atoms. The same forces interacting between the carbon atom would be the same for the others.

Next would be methane. Methane is a hydrocarbon composed of a single carbon atom bonded covalently with four hydrogens. The electrons within the hydrogen atoms repel each other causing them to be dispersed around the carbon atom to form a   tetrahedral shape. While more complex, the other two are continuous structures made from carbon atoms bonded to gather to form crystal structures.

Graphite is considered to be a crystal structure, just like a diamond. However, the biggest difference between them is their atomic and crystal frameworks. Diamonds have a rigid 3-dimensional structure whilst graphite is composed of 2d planes of carbons with carbon-carbon double bonds connecting the layers. Due to this, a diamond would be more complex then graphite

you didnt put any of the following

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