Answer:
NH₃
Explanation:
mass H = 6.10 grams
mass N = 28.00 grams
mass cpd = (6.10 + 28.00)grams = 34.10 grams
%H/100wt = (6.10/34.10)100% = 17.9% w/w
%N/100wt = (28.00/34.1)100% = 82.1% w/w
%/100wt => grams/100wt => moles => ratio => reduce => emp ratio
%H/100wt = 17.9% w/w => 17.9g => (17.9/1)moles = 17.9 moles H
%N/100wt = 82.1% w/w => 82.1g => (82.1/14)moles = 5.9 moles N
Ratio N:H => 17.9 : 5.9
Reduce mole ratio (divide by smaller mole value) => 17.9/5.9 : 5.9/5.9
=> 3HY:1H empirical ratio => empirical formula NH₃ (ammonia)
To get the empirical formula of this compound, we take a basis of 100 grams which means each percentage is equivalent to 1 gram. Hence there is 32.39 grams sodium, 22. 53 grams sulfur and 45.07 grams oxygen. We convert each mass to their moles by dividing by their respective molar mass. Na: 1.408, S:0.704 and O:2.82. divide each with the lowest: Na: 2: S: 1 and O:4. Hence the formula is Na2SO4.
Atoms are the building blocks of all matter
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.
Neutrons were discovered by James Chadwick<span> in 1932, when he demonstrated that penetrating radiation incorporated beams of neutral particles. Neutrons are located in the nucleus with the protons. Along with protons, they make up almost all of the mass of the </span>atom<span>.
Hope this helps. </span>
