in order to determine empirical formula we have to determine the mole ratio of the given elements
Let the total mass of the compound is 100g
as given that the compound has 40% sulfur , so mass of sulfur = 40g
as given that the compound has 60% oxygen, so mass of oxygen = 60g
let us calculate the moles of each element
Moles of sulfur = mass / atomic mass = 40 / 32 = 1.25
moles of oxygen = mass / atomic mass = 60/ 16 = 3.75
In order to get simple ratio of moles we will divide both the moles with least number of moles which is 1.25
moles of sulfur = 1.25 / 1.25 = 1
moles of oxygen = 3.75 /1.25 = 3
So empirical formula will be SO₃
Answer is: A. They opposed the use of energy released during nuclear fission for military purposes.
Hahn, Strassmann and Meitner were not engaged in nuclear weapons research during World War II.
Otto Hahn (1879 - 1968) became a passionate campaigner against the use of nuclear energy as a weapon.
Hahn and Strassmann discovered nuclear fission (nuclear fission of uranium in 1939).
Answer:
C) 
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
The expression of the pH of the calculation of weak acid is:-
Where, C is the concentration = 0.5 M
Given, pH = 2.94
Moles = 0.100 moles
Volume = 1.00 L
So, 
C = 0.100 M



Answer:
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The number of protons must differ between two different elements