I believe it is the nucleus.
For the first question-a bicep is a large muscle in the upper arm which flexes the arm and forearm, a tricep is a large muscle at the back of the upper arm and a deltoid is a thick triangular muscle covering the shoulder joint and used for raising the arm away from the body.
Radioactive decay occurs when an atom has either to many or to few neutrons and becomes unstable and start to emit radio active radioactive radiation and the atom start to decompose.
At the end two things can happen either the atom will transform in a new element with a lower atomic # and atomic mass # or the remaining neutron will transform into an electron and be on its own way
Surface tension decreases when temperature increases because cohesive forces decrease with an increase of molecular thermal activity
<h2>1 nature</h2><h2>2 ecology </h2><h2>3 water cycle </h2><h2>4 carbon cycle</h2><h2>5 chemical cycle </h2><h2>6 ecosystem </h2><h2>7 food chain </h2><h2>8 producers</h2><h2>9 consumers</h2><h2>10 decomposer</h2>