Which of the following liquids has the highest surface tension? water oil bromine mercury

Option (d) is the correct answer.

Explanation:

When the surface of a liquid resists any external force due to the cohesive nature of its molecules it is known as surface tension.

These cohesive forces between the molecules are shared with all the neighboring molecules. The molecules at the surface does not have any neighboring molecules thus, they are attracted by the molecules on and below the surface.

This reduces the surface area and increases the surface tension of the liquid. More tightly the molecules are attracted, more will be the surface tension.

Out of the given options, mercury has the highest surface tension.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.