Isotopes with unstable nuclei are __1__ and are called __2__. The __3__ of radioisotopes decay to __4__nuclei plus emission of l
arge amounts of __5__ . The radiation may be alpha, __6__, or gamma. __7__ radiation consists of alpha particles (positively charged __8__ nuclei) that are easily stopped by a sheet of paper. Beta radiation is composed of fast-moving particles, which are __9__. Beta radiation is more penetrating than alpha radiation; it is stopped by __10__. __11__ radiation is electromagnetic radiation. Gamma radiation has no __12__ or electrical charge. It is extremely penetrating. __13__ bricks and __14__ reduce the intensity of gamma radiation but do not completely __15__ it.
Heat of fusion is <span>the </span>heat<span> absorbed by a unit mass of a given solid at its </span>melting<span> point that completely converts the solid to a liquid at the same temperature. We use this concept to calculate the mass of copper. We do as follows:
H = m(Hfus) 112.4 = m (13.0) ( 1 mol / 63.55 g ) m = 549.4631 g -------> OPTION 3</span>
Secondary succession occurs in areas where a biological community has already existed but some or all of that community has been removed by small-scale disturbances that did not eliminate all life and nutrients from the environment.