My very eager mother just served us nine pizzas
Hi there!
Recall the equation for centripetal force:

We can rearrange the equation to solve for 'r'.
Multiply both sides by r:

Divide both sides by Fc:

Answer:
A pure substance consisting only of atoms with the same number of protons in their nuclei-these appear on the periodic table
Oxygen
Hydrogen
Carbon
Sulfur
Phosphate
Nitrogen
Magnesium
Calcium
Potassium
Chlorine
(I know that these are more examples than needed, but you can use any)
I used to wish that I can fly