Isotopes

What good are they?

Isotopes•forms of an atom with varying numbers of neutrons•can be identified by their weight

Some are radioactive and some are stable.

•neutrons “fall off”•emission can be detected and traced•molecules “decay” into another kind of molecule

Some are radioactive and some are stable.

•neutrons “fall off”•emission can be detected and traced•molecules “decay” into another kind of molecule

•neutrons stay put•remain as they are over time

Some are radioactive and some are stable.

Monarch Migration video (NOVA)

http://www.pbs.org/wgbh/nova/nature/journey-butterflies.html

Until now, there's never been a good way to find out exactly where the Mexican monarchs spend their summers and reproduce. Butterfly tagging programs are popular. But only a few tagged butterflies are found among the millions of monarchs in the wintering grounds. Butterflies are too small to track with radios or satellites.

In nature, an element occurs as a mixture of isotopes which can vary according to geography and other environmental factors

How can isotopes be used to study monarch migration?

How can isotopes be used to study monarch migration?

Researchers analyze wing membranes because their isotopic composition does not change after they are formed at the breeding site.

radioactive isotopes can be used to:

•trace atoms in metabolism•diagnose medical disorders•monitor chemical processes in the body

date fossils

Anthropological and forensic problems?

As well as in determining past climates from oxygen isotopes in ice and ocean organisms

Which oxygen isotope gets trapped in ice (as a result of precipitation) and in the shells of ocean organisms is temperature dependent so . . .

Which oxygen isotope gets trapped in ice (as a result of precipitation) and in the shells of ocean organisms is temperature dependent so . . .

ratios can be used to determine past temperatures

ratios can be used to determine past temperatures

ice core sampling

ice core storage facility

Uses for isotopes:•tracking migration•medical uses•forensic uses•environmental changes (like climate changes and pollution movement)•radioactive isotopes can be used for aging things

the end