The sum of the protons and neutrons in an atom equals the
a. atomic number.
b. number of electrons.
c. atomic mass.
d. mass number.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )