Questions

We know that polar substances are soluble in polar solvents and non polar substances are soluble in non-polar solvents only. Here the hydrocarbons are non-polar molecular substances and water is a polar solvent. So water can't dissolve hydrocabons.

Hence, as hydrocarbons are non-polar substances, they are insoluble in water as it is a highly polar solvent. 

A metalloid is an element with properties between metals and non metals or the mix of both.

The six metalloids are arsenic, silicon, germanium, boron, antimony and tellurium.

Hence, silicon is the only metalloid in the given list.

Goa

Evaporation is the process that allows water to enter into the atmosphere.

Sunlight turns liquid water into water vapor which then rises higher into the atmosphere and forms into clouds.

Plants, too, help water get into the atmosphere through a process called transpiration.