In order for convection to occur, you must have

We have a colorless transparent liquid. it looks like water. we seperated it into a solid and a liquid by evaporration and condention was this a chemichal or a physical seperation a. chemical seperation b. physical seperation

Energy flows from the producer level to the level. is called

Which of these is constant for all types of electromagnetic radiation in a vacuum? select one: a. wavelength b. frequency c. photon energy d. amplitude e. velocity