Students not only want to know how old a fossil is, but they want to know how that age was determined.Some very straightforward principles are used to determine the age of fossils.The article is in straightforward language and the non-technical reader could profitably work through it.
Isotopes are distinguished from each other by giving the combined number of protons and neutrons in the nucleus.
For example, uranium 235 is the isotope of uranium that has 235 protons and neutrons in its nucleus rather than the more commonly occurring 238. noun A nearly identical person; near double: Like his isotope Paglia, Rush Limbaugh can be counted on to bury the occasional nugget of truth beneath his avalanche of infuriating extrapolation and phony statistics/It actually IS you.
You've probably heard people talk about radiation both in fiction and in real life.
For example, when the Enterprise approaches a star on "Star Trek," a member of the crew might warn about an increase in radiation levels.
And in the aftermath of the March 2011 earthquake and tsunami that struck Japan, a nuclear crisis raised fears about radiation and questions about the safety of nuclear power.