Formation of red blood cells

Secretion

Absorption

Protection

The object's speed increases and decreases as it moves around the circle.

The magnitude of velocity remains constant, but its direction continuously changes around the circle.

The object moves with a changing velocity along a straight path.

The velocity remains unchanged in both magnitude and direction throughout motion.

Because they contain the same number of neutrons

Because they have similar atomic mass

Because they are found in the same physical state

Because they have the same number of protons and electrons