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.
HNO3 and H2SO4 are Arrhenius acids which will increase the concentration of H+ when dissolved in water.
KOH and Ca(OH)2 are Arrhenius bases that increase the concentration of OH- when dissociated in water.
Answer:
d. its effective nuclear charge is lower than the other noble gases.
Explanation:
Xenon belongs to group O on the periodic table. Most of the elements here are unreactive.
Due to the large size of Xenon, the outermost electrons have very low effective nuclear charge. Effective nuclear charge is the effect of the positive charges of the nucleus on the electrons in orbits. This effect decreases outward as atomic shell increases.
Xenon has a very large atomic radius and there is weak a nuclear charge on the outermost electrons. The more electronegative elements would be able to attract some of its outermost electrons easily and form chemical bonds with xenon much more readily.
Explanation:
It is often desirable to determine the mass percent of elements in a given compound.
To determine the mass percent of elements:
- Evaluate the formula mass of the compound. This is done by summing the atomic masses of the atoms in the compound together.
- The mass percentage is determined by pacing the mass contribution of each element or group to the formula mass of the compound and multiply by 100.
Learn more:
Percent by mass brainly.com/question/5544078
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