Environmental Science (Chapter 1 )

Match it! Select the correct answer from the pull down...Good luck!

An approximate age of something compared to some other event in history is called____________

________________ is the numeric age of an object or event, often stated in years before the present, an example is radiometric dating.

________________ is an educated guess.

__________________ is an object launched into space by NASA around the earth in 1990 to provide information about the universe.

If you began with 300g of a parent isotope, you would have 75g of that isotope after two half–life of that isotope. How many grams are left after 3 half–lives?

A(n) _____________ is a substance that cannot be broken down into a simpler substance.

Which of these is NOT a reason why does Earth has less craters than Mars?

What do scientists count in order to learn the age of a planetary surface? __________________