*Hydrogen is the most abundant element representing nearly three quarters of the mass of the universe.
*Hydrogen is found in the water that covers 70% of the surface of our planet as well as in all organic matter.
*Hydrogen is the simplest element in the universe. It is composed only of one proton (p) and only one electron (e-).
*Hydrogen is the lightest element of all elements and gases; it is 14 times lighter than air. A "spill" of hydrogen gas immediately diffuses into the air and pollutes neither the ground nor the water table.
*Hydrogen is invisible, odorless and nontoxic. It does not cause acid rain, does not deplete the ozone layer and does not generate dangerous emissions.
<span>Read
the spelling pattern rule. Nouns that end in a consonant + y are made
plural by adding -ies. some examples are babies, ponies and spies. Which
does not follow the pattern rule?
