Why does the energy required to remove an electron change as it does?

In all living cells dna controls cellular activities by

Consider the nuclear equation below. 239/94 pu—-> x+ 4/2 he. what is x?

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o