There are 18 Elements in the fifth period.
Explanation:
An epidemic (from Greek ἐπί epi "upon or above" and δῆμος demos "people") is the rapid spread of disease to a large number of people in a given population within a short period of time.
The angle of incoming solar radiation influences seasonal temperatures of locations at different latitudes. ... At higher latitudes, the angle of solar radiation is smaller, causing energy to be spread over a larger area of the surface and cooler temperatures.
Properties of metals:
High melting points
High density
Ductile
Malleable
Good conductors of electricity
Good conductors of heat
I think if you added a proton you would have chlorine.
The noble gasses are the he chemical elements in group 18 of the periodic table. The gasses in this family include helium, neon, argon, krypton, xenon, and radon. All these gasses are colorless are oderless, elements in this family have atoms with a full outer shell of electrons. They are also called inert gasses.
Six valence electrons