The gravitational pull generates this cool thing called tidal force, which kinda pushes the water to the side closest to the moon. When the tide is high, that means the moons closer to that point than somewhere else.
Two sides will always have high tide and two sides will always have low tide.
Answer:
Ammonia is the richest source of nitrogen on a mass percentage basis because it has 82.35% of nitrogen by mass.
Explanation:
Percentage of element in compound :

(a) Urea, 
Molar mass of urea = 60 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 2

(b) Ammonium nitrate, 
Molar mass of ammonium nitrate = 80 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 2

(c) Nitric oxide, NO
Molar mass of nitric oxide = 30 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 1

(d) Ammonia, 
Molar mass of ammona = 17 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 1
Ammonia is the richest source of nitrogen on a mass percentage basis because it has 82.35% of nitrogen by mass.
Chloroplasts is the answer
<span>The lungs are the main organ of the respiratory system, which carries oxygen through the body by means of red blood cells and picks up carbon dioxide, a waste gas, to expel from the body when an organism exhales. The trachea filters the inhaled air and branches into the bronchi, where the air tubes carry air directly into the lungs. The diaphragm is the main muscle of the respiratory system, contracting to increase the volume of the lungs and carry air into the body and expanding to force air out of the lungs.</span>
Answer: option 4. polar, with the chlorine end having a partial negative charge.
Explanation:
1) A polar bond is a covalent bond in which the electrons are pulled more strongly by one of the atoms and then they are not evely distributed between the two linked atoms.
2) That happens when the two atoms have diferent electronegativities.
3) As the per periodic table trend of the electronegativity, you can predict that the electronetativity of Cl is higher than that of P.
In fact, in a table of electronegativities you can find that the electronegativity of Cl is 3.16 while the electronegativity of P is 2.19.
This is a 3.16 - 2.19 = 0.97 difference.
As explained, that difference means that Cl will pull the electrons more strongly resulting if a partial negative charge on Cl and a partial positive charge on P, i.e. a polar bond.