active transport requires the usage of energy in the form of ATP to  move something against is concentration gradient. Facilitated  diffusion is a form of simple diffusion i â¦ n that the substance moves  along with its concentration gradient, but it requires the use of a  transport protein.
Quick Answer. The atomic mass of the element neon is 20.18 amu, or atomic mass units. This number, which appears on the periodic table underneath the chemical symbol for neon, Ne, represents the weighted average of the isotopic masses of neon's isotopes based on their abundance in nature. Continue Reading.
The mass number is the number of protons added to the number of neutrons. Hydrogen only contains 1 proton and no neutrons, so that gives a mass number of 1. However, there are some isotopes of Hydrogen, in other words, some atoms that have more than zero neutrons. For example, Deuterium has 1 neutrons hence an atomic mass of 2 and Tritium has 2 neutrons hence an atomic mass of 3. The number you see for atomic mass in a periodic table is an average of the abundance of the isotopes, which is why it's a decimal like 1.007941.00794 and not a whole number.