What is the mass of a 7.91 cm cubed piece of lead having a density of 11.34 g/cm cubed

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Suppose that during that icy hot lab 65,000 j of energy were transferred to 450 g of water at 20°c what would have have been the final temperature of the water

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