How heat affects objects

[holyduckie]

How does heat ( including coolness ) affect these objects ?

(i) The brightness ( light output ) of light sticks

(ii) Magnetism of magnets

Can someone also provide some websites for my reference ? Thanks in advance.

[heathfield]

Light-sticks - http://dwb.unl.edu/Chemistry/DoChem/DoChem113.html

[heathfield]

Ferrous particles in a hot material, such as in molten rock, or clay in a potter's kiln, will pick up magnetism from the earth's magnetic field as the material cools. This is how scientists know about reversals in the polarity of the earth's magnetic field through the study of magnetism in ancient rocks.

[fo3nix]

Magnetism is just an ordering of the stuff in the material. The more ordered it is (in the same direction perhaps), the more magnetic it is. As you may know, the hotter something is, the more the stuff inside shakes about, and hence the more random it is. So when it's more random, it's less ordered, and hence less magnetic.