Aradioactive isotope has a half-life of 3 hours. if a scientist has 30 grams of the isotope, how much is left after 15 hours

Which object forms when a supergiant runs out of fuel? a red giant a black hole a white dwarf a neutron star

According to the diagram, what sources contribute to the phosphorus found in soil? according to the diagram, phosphorus found in soil contributes phosphorus to what other sources?

Predict the reactants of this chemical reaction. that is, fill in the left side of the chemical equation. be sure the equation you submit is balanced. (you can edit both sides of the equation to balance it, if you need to.) note: you are writing the molecular, and not the net ionic equation. > cacl2(aq) + h20(l)