Which of the following is not an example of a subatomic particle? electron photon neutron proton

The correct answer is a photon.  

A photon refers to a particle signifying a quantum of light or other electromagnetic radiation. A photon carries energy equivalent to the radiation frequency, however, exhibits zero rest mass.  

A subatomic particle refers to a unit of energy or matter, that is, the basic makeup of all the matter. On the basis of modern atomic theory, an atom exhibits a nucleus, also known as the core or its center. The nucleus comprises subatomic particles, that is, neutrons and protons. The neutrons are neutral particles, and the protons are positively-charged particles. A cloud of very small subatomic particles known as electrons surrounds the nucleus. The electrons are negatively charged particles.  

the answer is true.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.