There are a lot:
Neon is a non metal element. Atomic mass of it is 20.
The element with an atomic mass of 40.078 amu is calcium. Calcium has an atomic number of 20.
We can find calcium as a non metal element. Atomic number of it is 20.
Neon is a non meta element. Atomic mass of it is 20.
The element with a mass of 30 and is a noble gas, other than neon, is krypton (Kr). With an atomic number of 36, krypton has 36 protons in its nucleus and typically has 44 neutrons in its most common isotope, giving it an atomic mass near 84.
The atomic mass of an element is the average mass of an atom of that element. For a gas with an atomic mass of 20, it could be calcium (Ca). Calcium has an atomic number of 20 and an atomic mass of approximately 40.08 grams per mole.
Neon
The element with an atomic mass unit (amu) of 20 and is a gas is Neon. Neon has an atomic number of 10 and is a noble gas found in the Earth's atmosphere.
Neon is a non meta element. Atomic mass of it is 20.
Neon is a non metal element. Atomic mass of it is 20.
Neon is a non metal element. Atomic mass of it is 20.
Calcium is a metal element. Atomic mass of it is 40.
The element with an atomic mass of 40.078 amu is calcium. Calcium has an atomic number of 20.
Neon.
Neon
Neon is a non meta element. Atomic mass of it is 20. Atomic number of it is 10.
The element with atomic number 20 is calcium. The mass number 23 indicates the total number of protons and neutrons in the nucleus of the atom. Since the mass number is 23 and the atomic number is 20, the number of neutrons in this calcium atom would be 3 (23 - 20).