helium

As a noun helium

is helium.

As an adverb he is

now.

As nouns the difference between calcium and helium

is that calcium is calcium while helium is helium.

As nouns the difference between helium and trioxide

is that helium is a colorless and inert gas, and the second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602 while trioxide is any oxide containing three oxygen atoms in each molecule.

In uncountable terms the difference between nitrogen and helium

is that nitrogen is molecular nitrogen (N₂), a colorless, odorless gas at room temperature while helium is a colorless and inert gas, and the second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602.

In countable terms the difference between nitrogen and helium

is that nitrogen is a specific nitrogen within a chemical formula, or a specific isotope of nitrogen while helium is a form or sample of the element.

In uncountable terms the difference between neon and helium

is that neon is neon signs, collectively while helium is a colorless and inert gas, and the second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602.

In countable terms the difference between neon and helium

is that neon is a neon tetra fish while helium is a form or sample of the element.

As an adjective neon

is extremely bright; fluorescent.

In uncountable terms the difference between helium and water

is that helium is a colorless and inert gas, and the second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602 while water is a chemical, found at room temperature and pressure as a clear liquid, having the formula H₂O, required by all forms of life on Earth.

In countable terms the difference between helium and water

is that helium is a form or sample of the element while water is a serving of water.

As a verb water is

to pour water into the soil surrounding (plants).

As nouns the difference between dihydrogen and helium

is that dihydrogen is (chemistry) the divalent radical formed from two separate hydrogen atoms or ions while helium is helium.

As nouns the difference between helicopter and helium

is that helicopter is helicopter while helium is helium.

As nouns the difference between helium and thelium

is that helium is a colorless and inert gas, and the second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602 while thelium is a nipple or papilla.