The answer is C because of the ionization energy trend
I believe this is the best one:
B. The volume of water will increase if cooled from 3°C to 2°C.
I don't think D) because water expands from 4°C to 0°C
"When liquid water is cooled, it contracts like one would expect until a temp of approximately 4 degrees Celsius is reached. After that, it expands slightly until it reaches the freezing point."
Answer:
a)The mass percentages of nitrogen and phosphorus in the compound is 24.34% and 26.95% respectively.
b) 14.78 grams ammonia is incorporated into 100. g of compound.
Explanation:
a) Ammonium dihydrogen phosphate that is
.
Molecular mass of ammonium dihydrogen phosphate = M
M = 115 g/mol
Percentage of an element in a compound:

Percentage of nitrogen:

Percentage of phosphorus:

b) Percentage of ammonia in 1 molecule of ammonium dihydrogen phosphate.
Molar mass of ammonia = 17 g/mol

Amount of ammonia in 100 grams of compound:
14.78% of 100 g of ammonium dihydrogen phosphate:

14.78 grams ammonia is incorporated into 100. g of compound.
Answer:
Valence electrons or outer electrons are most important as they participate in bonding. The octet rule states that atoms gain, lose, or share valence electrons to have filled energy levels.. this gives atoms a stable configuration like that of the nearest noble gas.
Answer:
Group 18th
Explanation:
The group 18th of periodic table which is composed of Noble gases mainly was missing from the Mendeleev's periodic table. The reason for this is that Noble gases are least reactive, therefore, it was difficult to predict such elements which do not react with other elements.