Of the following, the most nonmetallic element is of the following, the most nonmetallic element is s se cl p br

Cl is the most non-metallic element.

Explanation:

Non-metals are the substance that tend to gain electron(s) in order to complete their octet.

When we move across a period in periodic table then there will be increase in electronegativity of the elements and also there will be decrease in size of elements.

Since, elements S and Se belongs to group 16. Whereas P is a group 15 element and both Cl and Br belongs to group 17.

Also, when we move down the group there will be increase in size of elements due to increase in number of shells. As a result, force of attraction decreases between the nucleus and valence shell of an element.

This means that smaller is the size of a non-metal more will be its ability to gain an electron. Hence, more will be its non-metallic character.

Out of Cl and Br, Cl is smaller in size and more electronegative than Br.

Thus, we can conclude that out of the given options Cl is the most non-metallic element.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%