How many molecules are in 0.5 mol?

Acombination reaction is when two or more combine to form one product. a decomposition reaction is when a substance breaks down into two or more simpler substances in a chemical reaction.

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

Why do astronauts in the space shuttle weigh less?