What is the net force one 0.2 kg ball when it hits a wall with acceleration of 10 m/s2

The movement of electrons between atoms is called an

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? the cloud is extremely hot. the cloud is visible primarily because it reflects light from nearby stars. the cloud is cool and lies between you and a hot star. the cloud is cool and very dense, so that you cannot see any objects that lie behind it.