The element phosporus is located to the right of the element magnesium along the same period in the periodic table. Which best describes the relationship of the elements?

Magnesium has a larger atomic number.
Phosphorus has a larger atomic mass.
Magnesium is in the same category as phosphorus.
Phosphorus has similar chemical properties as magnesium.

the answer is B Phosphorus has a larger atomic mass.

Explanation:

took the test :]

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.