A typical spectrophotometer has a path length (the distance light travels through a sample) of 1 cm. Light travels at approximately 3.0 x 108 m/s in vacuum. How long does it take (in ns) for light to travel 1.0 cm

This is what i found on google “according to the collision theory, the following criteria must be met in order for a chemical reaction to occur: molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break. molecules must collide with the proper orientation.” i hope this information you.

Planck decided to assume that atoms could only vibrate at certain frequencies that were whole numbers eg 2f, 3f and so on. others used to think that atoms vibrate continuously