Introductory astronomy1. light is absorbed and emitted in the form ofwhich are "packets" ofelectromagnetic radiation that carry a specific amount of energy. photonsionsexcited atomsprotons2. light is characterized by which two properties? point)electromagnetic energy and wavelengthwavelength and frequencyfrequency and radiationoelectromagnetic radiation and gamma rays

Light ... and all other forms of electromagnetic radiation ... behaves
as if it were a stream of 'packets' that we call 'photons', each one
carrying a specific amount of energy.

Light  ... and all other forms of electromagnetic radiation ... is
characterized by its wavelength.  That is, once you state its wavelength,
you've stated everything there is to know about the light, including its
frequency, and the energy carried by each photon. 

Your answer is 1.5 hope i  

If its history of, then b) because a) implies only present day (now)