Why do some of the staples stick to the nail?

Explanation:

When the bar magnet picks up a nail, it magnetizes the nail. The domains of the nails temporarily align in one direction and it acts like a magnet. The nail becomes a temporary magnet. Therefore, when the tip of the nail touches some staples, the staples get attracted by the nail and sticks to it.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.