When aluminum, al, metal is dipped in an aqueous solution of hydrochloric acid, hcl, hydrogen gas, h2, is produced with the formation of an aluminum chloride, alcl3, solution. write the balanced chemical equation showing the phases of reactants and products. express your answer as a chemical equation including phases.

2Al (s) +  6HCl (aq) → 2 AlCl3 (aq)  +  3H2 (g)↑  

Explanation:

- We can put an up arrow to H2 cause as it is a gas, it can be released to the atmosphere.

- Aluminum as metal must be solid.

- As we have two solutions, both are aqueous phase.

- The stoichiometry must match on both sides of the reaction to have the same amount of elements of each compound.}

Reactants : 2 Aluminun

6 Hydrogen

6 Chloride

Products:

2 Aluminun

2.3 = 6 Chloride

3.2 = 6 Hydrogen

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.