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 Shrimps heart is located on its head.

Sukhna Lake is in Chandigarh, India.

It is a reservoir at the foothills of the Himalayas. It covers an area of 3 km². This rainfed lake was created in 1958 by damming the Sukhna Choe, a seasonal stream coming down from the Shivalik Hills.

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.