It is C. because the sunlight bounces off the moon causing it to be visible only at night.
To solve this questions you first need to find the number of moles of barium phosphate you have. The molar mass of barium phosphate is 601.93g/mol.
24.4/601.83 = 0.0402 moles barium phosphate
Then you need to use avagadro’s number, 6.022 x 10^23, which is the number of molecules or formula units in a mole.
6.022 x 10^23 * 0.0402 = 2.42 x 10^22 formula units
The answer is
C. A single replacement reaction (acid reactions)
An example would be the reaction between simple metal Potassium (K) and Water (H2O), resulting in a much solid compound called Potassium Hydroxide (KOH) and hydrogen gas is set free.
K+H2O --> KOH
Nonessential amino acids can be made by the body, while essential amino acids cannot be made by the body so you must get them from your diet.
Nonessential acids : glutamine, proline, glycine etc
Essential acids: lysine, leucine etc.