Argon has 24 known isotopes.
B - Atomic number. Dmitri Mendeleev organised the table according to atomic weight, however this caused problems with elements such as iodine and tellurium, Iodine has a higher mass, but a lower atomic number. And to make iodine in the same group as similar elements (halogens), Mendeleev had to break his own rules and put it before tellurium in the table. Moseley fixed this problem by ordering the elements according to atomic (proton) number.
Answer:
62.5 moles of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Finally, we shall determine the number of mole of O₂ needed to react with 5 moles of C₈H₁₈. This can be obtained as shown below:
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Therefore, 5 moles of C₈H₁₈ will react with = (5 × 25) / 2 = 62.5 moles of O₂.
Thus, 62.5 moles of O₂ is needed for the reaction.
Answer:
c
Explanation: just a chemachal
Answer: Empirical formula is 
Explanation: We are given the masses of elements present in a sample of compound. To evaluate empirical formula, we will be following some steps.
<u>Step 1 :</u> Converting each of the given masses into their moles by dividing them by Molar masses.
Molar mass of Carbon = 12.0 g/mol
Molar mass of Hydrogen = 1.0 g/mol
Molar mass of Oxygen = 16.0 g/mol
Moles of Carbon = 
Moles of Hydrogen = 
Moles of Oxygen = 
<u>Step 2: </u>Dividing each mole value by the smallest number of moles calculated above and rounding it off to the nearest whole number value
Smallest number of moles = 13.76 moles
<u>Step 3:</u> Now, the moles ratio of the elements are represented by the subscripts in the empirical formula
Empirical formula becomes =
