Which kind of molecule does the diagram represent?

It is a triglyceride

Explanation:

A triglyceride is a molecule that contains a glycerol group and three fatty acids linked by an ester linkage. A fatty acid is a molecule formed by a long linear hydrocarbon chain, of different length or number of carbon atoms, at the end of which is a carboxyl group. These chains can be saturated (with hydrogen) or when there are double bonds in the chain  this reduces the available places of hydrogen that's why it's called unsaturated.

In the image you can see on the right the glycerol group. And the three fatty acids extending to the left. The top one is an example of a saturated fatty acid, and the two below unsaturated.

Triglycerides are generally solid at room temperature and are therefore called fats. For example, the fat that constitutes us is mostly formed by triglycerides.

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.