If a substance can be separated by physical means and it is not the same throughout, what is it? a: a homogeneous solution b: a heterogeneous mixture c: a pure substance d: an element e: a compound

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

The seven sisters, seven stars located more than 400 light-years away in the taurus constellation can be seen here with venus and another constellation, orion. the seven stars stay grouped together but seem to move, like the planet venus. why do stars seem to move like planets in the night sky?