In the symbol 42he, the subscript 2 is the for helium and the superscript 4 is the for helium. atomic mass; atomic number atomic number; atomic mass mass number; atomic number atomic number; mass number

Un jugador de beisbol batea un foul recto en el aire. la pelota deja el bate con una rapidez de 120 km/h. en ausencia de resistencia del aire. ? cual sera la rapidez de la pelota cuando la atrape el catcher

Estimate the schwarzschild radius (in kilometers) for a mini-black hole formed when a superadvanced civilization decides to punish you (unfairly) by squeezing you until you become so small that you disappear inside your own event horizon. (assume that the your weight is 50 kg)

Use 4 to 5 complete sentences, explain the concepts of beats and how beats are produces.