Of the 20 amino acids, how many amino acids are considered essential? why are they called essential?

What processes occur in a plant leaf?

Which gas law has the assumptions of a fixed amount and pressure of a gas

Is adding chocolate syrup to milk a chemical or physical change?

According to the Bohr model of an atom, what happens when an electron moves from the second energy level to the third energy level and then back to the second energy level? Energy is absorbed and then stored in the atom.

What is the molarity of 100 g of HCI in 0.75L of solution?

What is hotter 17 degrees celcius or 58 degrees Fahrenheit

How do aqueous solutions of ionic and molecular compounds differ

Which reaction represents an unbalanced neutralization reaction? Na + H2O NaOH + H2 HNO3 + NaOH NaNO3 + H2O NaNO3 + H2O HNO3 + NaOH H2O H2 + O2

How does the health of polar bears indicate the health of the environment

Our body needs iron. Certain foods are rich in iron and iron tablets are usually recommended by doctors. but neither the food nor tablets are hard like iron? Why?