a newton's cradle, those are always cool.
Democracy
Required, no. A gift is never required for any occasion.
Chemistry I would think. Chemistry is the kind of science in which the reaction of two chemicals is observed.
Typically it would be a bachelors of science degree (BS) with a major in political science.
Buddhists are people too, and so I think it depends on the person you are giving the gift too. Some branches of Buddhism do not put boundaries on what kinds of things are acceptable, and so it would depend on the kind of BUddhist your friend is. Ultimately, gift giving is a kind of action that transcends boudaries and any person who does not feel appreciation for a gift is already breaking Buddhist values. If the gift is from the heart, i don't see why it would not be a good gift.
For young children a gift basket with toys or games and candy would be appropriate. Another option to consider giving the child would be some kind of educational DVDs.
Green Card.....hahaha
the gift of healing
Amazon seems to recommend gift baskets. If you know what kind of interests the person you are sending the gift has, try looking for something that would be appealing for them and includes a bunch of mini gifts inside.
The would be an appropriate gift at a wedding or a funeral. Kind of ironic if you think about it. The beginning of a new life and the end of a life.
All jobs deal with science to a certain extent. Most common of the science professions, however, would be a scientist.
the gift of healing