Explanation:
It is given that lattice energy is -701 kJ/mol.
Whereas it is known that realtion between lattice energy and radius is as follows.
Lattice energy 
where,
= +2, and
= -2
Therefore, lattice energy of AB = 
= 
= -2804 kJ/mol
Thus, we can conclude that lattice energy of the salt ABAB is -2804 kJ/mol.
Answer:
root-mean-sqaure = 2.77 m/s
average = 2.72 m/s
The root-mean-square is always the largest because it takes account of the variance of the spread of the data. The increase is related to the fact that the data varies to sample.
Explanation:
The rootmean-square (R) is the square root of the squares of the valeus divided by the number of the datas.


R = √(46.03)/6
R = 2.77 m/s
The average speed is the sum of the speeds divided by the number of datas:

A = 16.3/6
A = 2.72 m/s
As per the rule, oxidation number of alkaline earth metals in their compounds is +2. Oxidation number of oxygen in it's compounds is -2(except peroxides) and the sum of oxidation numbers of all the elements of a neutral compound is zero.
The answer to your question is the first one!
In order to calculate the mass of nitrogen, we must first calculate the mass percentage of nitrogen in potassium nitrate. This is:
% nitrogen = mass of nitrogen / mass of potassium nitrate
% nitrogen = 14 / 101.1 x 100
The mass of nitrogen = % nitrogen x sample mass
= (14 / 101.1) x 101.1
= 14 grams
The molar weight of nitrogen is 14. Each mole of urea contains two moles of nitrogen. Therefore, for there to be 14 grams of nitrogen, there must be 0.5 moles of urea.
Mass of urea = moles urea x molecular weight urea
Mass of urea = 0.5 x 66.06
Mass of urea = 33.03 grams