Produced in the pineal gland, which hormone plays an important role in the regulation of the human sleep cycle

Marked by differences in activity and appearance, 'solitary' and 'gregarious' are two behavioral phases of which insect.

The square root of 25 is equal to plus or minus 5.

A googol is smaller than a billion

Every square is a rectangle

An obtuse triangle can have more than one obtuse angle.

All even numbers are composite numbers

In any chemical reaction, the total amount of matter in the system remains exactly the same.

The rusting of iron is considered a physical change because only the appearance of the metal is altered.

The atomic number of a chemical element is equal to the number of neutrons found in its nucleus.

Sterling silver is a term used for jewelry made of 100% pure silver.

The shortest distance between two points is always a straight line, regardless of the geometry of the surface.

Sound travels faster in water than it does in air.

Zero is considered an even number.

The number 1 is the smallest prime number.