1=Explain what the mass number and atomic number tell us about an element . 2=Calculate numbers of subatomic particles using mass numbers and atomic numbers . 3=Demonstrate electron configurations of your specific elements in the periodic table 4=Metals and non metals : Identify where metals and non - metals are found on the periodic Table . 5=Demonstrate which metals are electron donors and non - metals are electron Acceptors 6=Identify elements in the periodic table according to the group and period that they are

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