In an elliptical orbit, there is a component of gravity that is along the path. This component can change the speed and can do work. Ch 10 Review Questions 1. Atoms are as old as the universe. The solar system would have taken some time to form, so atoms would be older.
Atoms are much smaller than the wavelength of visible light.
When atoms or molecules hit the dust particles or grains of soot, this is a collision and gives an impulse to the particles. This force then causes the particles to accelerate and move. We see the resulting movement, or change in movement. A molecule is composed of more than one atom. Two elements, hydrogen and oxygen, make up water.