Cesium-137 is a radioactive byproduct of the fission process. Much Cesium-137 was deposited in the Bikini Atoll (in the Southwestern Pacific Ocean) during atomic bomb tests of the 1940s. How many years will it take 128-grams of Cesium-137 to decay to only 4-grams of Cesium-137 if its half-life is 30 years?

answer

fusion: the energy source of stars. the energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. when the core is hot enough, nuclear fusion commences. fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

hope it

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

there are two significant figures.

answersilicon (si); oxygen (o);