Which is an example of the electromagnetic force?

A compass needle points north toward Earth’s magnetic pole.
An iron nail rolls off a table and falls to the ground.
The moon pulls on the water in Earth’s oceans, causing tides.
Protons that make up a nitrogen atom stay together in the nucleus.

The “death throes” of stars are amongst the most complex phenomena in all of astronomy, and the “corpses” of stars amongst the most energetic and exotic objects in existence. beginning at the end of the core helium fusion stage in a star’s life, describe in detail the post-main sequence development of both (a) a 1.0 solar mass star, and (b) a 25.0 solar mass star. in what significant ways do they differ? what role does each of these types of stars play in the "star-gas-star" cycle and the evolution of chemical elements in our galaxy?

True or false graphs must include scales that increase by the same amount

It is really hard for me right know