What is the half-life of an isotope if 125 g of a 500 g sample of the isotope remain after 3.0 years

What method(s) do plants use to obtain nitrogen? select all that apply. absorb it from the atmosphere use bacteria to convert nitrogen to usable form obtain usable nitrogen compounds from the soil absorb nitrogen from water taken in at the roots

How have the greenhouse gasses increased from the year 2000 to 2018

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false