Atoms don’t absorb all wavelengths of light because of… a. Their valence electrons
b. Their shells
c. Their color
d. They do absorb all wavelengths of light

b. Their shells

Explanation:

The electronic shell of atoms represents the energy levels in a particular atom.

To understand the way atoms absorb energy, we must know that the wavelength absorbed is commensurate with the energy of the atom. This available energy allows for specific amount of energy to be absorbed.

Therefore, the electronic shell in an atom determines the absorption wavelength of the atom.

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.