If an isotope of some element has a half of 300 years about how much of the isotope will be in sample after 300 years

A half-life is how long an isotope takes to break down. A 300 year half life means that half of the sample will be left after 300 years.

the national environmental policy act (nepa) is a united states environmental law that promotes the enhancement of the environment and established the president's council on environmental quality (ceq). the law was enacted on january 1, 1970. to date, more than 100 nations around the world have enacted national environmental policies modeled after nepa.

frogs. the lower the ph the higher the acid content. frogs have the highest tolerance in this scenario.