Answer:
Henry Moseley.
Explanation:
Hello,
Henry Moseley's work stated that it is better to organize the periodic table in the light of the atomic number (which accounts for the amount of protons and electrons) instead of the atomic mass, because atomic numbers are not arbitrarily assigned as long as they have the aforesaid physical basis.
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Answer: the pH is 11.78
Explanation:Please see attachment for explanation
Trace fossils provide us with indirect evidence of life in the past, such as the footprints, tracks, burrows, borings, and feces left behind by animals, rather than the preserved remains of the body of the actual animal itself. so i would say B.
Answer:- 14.9 M
Solution:- Given commercial sample of ammonia is 28% by mass. Let's say we have 100 grams of the sample. Then mass of ammonia would be 28 grams.
Density of the solution is given as 0.90 grams per mL.
From the mass and density we could calculate the volume of the solution as:

= 111 mL
Let's convert the volume from mL to L as molarity is moles of solute per liter of solution.
= 0.111 L
Now, we convert grams of ammonia to moles on dividing the grams by molar mass. Molar mass of ammonia is 17 gram per mole.

= 1.65 mole
To calculate the molarity we divide the moles of ammonia by the liters of solution:

= 14.9 M
So, the molarity of the given commercial sample of ammonia is 14.9 M.
Answer: 1.
2. 3 moles of
: 2 moles of 
3. 0.33 moles of
: 0.92 moles of 
4.
is the limiting reagent and
is the excess reagent.
5. Theoretical yield of
is 29.3 g
Explanation:
To calculate the moles :

The balanced chemical equation is:
According to stoichiometry :
3 moles of
require = 2 moles of
Thus 0.33 moles of
will require=
of
Thus
is the limiting reagent as it limits the formation of product and
is the excess reagent.
As 3 moles of
give = 2 moles of
Thus 0.33 moles of
give =
of
Theoretical yield of
Thus 29.3 g of aluminium chloride is formed.