21. an electron is excited to a higher energy level with 5.3 units of energy. when it relaxes to the ground
state, the emitted photon will have which of the following energies?
a. greater than 5.3 units
b. 5.3 units
c. less than 5.3 units
d. some integer multiplied by 5.3 units

Aspirin has a density of 1.40 g/cm3 what is the volume in cubic centimeters of a tablet weighing 320 mg ?

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

Air can be considered a mixture. which statement does not explain why?