More than one atrium is called "atria." The term "atria" is the plural form of atrium.
A group of alligators is called a congregation.
Compounds, that's how it's called
a compound is what i thank to i learned that in 5th grade.
A mixture is a substance that has more than one component stirred together but does not undergo a chemical reaction. The components of a mixture can be physically separated from each other.
The right side of the heart has only one ventricle, called the right ventricle. It receives deoxygenated blood from the right atrium and pumps it to the lungs for oxygenation.
The atrium. (Plural: atria.)
more than one lynx is call lynxes
you call them possums if your talking about more than 1
More than one fisherman is fishermen
Ants
Fish
swans
A group of alligators is called a congregation.
Vampiresses.
Pegasi I think.
Polygamy.
UniversesNo one can surely answer that, but some scientists believe that there are more than one universe. They call this multiverse.