phosphorus has an atomic mass of 31 and an atomic number of 15, so the number of nuetrons must be?

What is the systematic name of the following compound? CaF2

Small beads of iridium-192 are sealed in a plastic tube and inserted through a needle into breast tumors. If an Ir-192 sample has an initial activity of 560 dpm, how much time is required for the activity to drop to 35 dpm (t1/2 = 74 days) ?

Based upon the valence electrons taken from the periodic table, the formula for rubidium (Rb) chlorine (CL) is:

Some nucleic acids are hormones that regulate life processes True or false

Practice of leaving the stalks of crops in the ground to anchor topsoil

State one major difference between having a nitrogen atom in a ring structure and having an oxygen atom in that structure

Can dowels be chopsticks, since both of them are wood?

Which electron configuration represents the electrons in an atom of Ga in an excited state?

Why are there so many volcanoes in and around japan

A liquid fuel mixture contains 30.35% hexane (c6h14), 15.85% heptane (c7h16), and the rest octane (c8h18). what maximum mass of carbon dioxide is produced