Answer: 6.3 x 10^-3 moles
Explanation:
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 atoms
So, 1 mole of potassium = 6.02 x 10^23 atoms
Z moles = 3.78 x 10^21 atoms
To get the value of Z, we cross multiply:
(3.78 x 10^21 atoms x 1mole) = (6.02 x 10^23 atoms x Z moles)
3.78 x 10^21 = (6.02 x 10^23 x Z)
Z = (3.78 x 10^21) ➗ (6.02 x 10^23)
Z = 0.63 x 10^-2)
Place the result in standard form
Hence, Z = 6.3 x 10^-3 moles
Thus, there are 6.3 x 10^-3 moles of potassium in 3.78 x 10^21 atoms of K.
Answer:
atomic number
Explanation:
isotope is a family of an element with the same atomic number but different mass number.
The atomic mass on the periodic table represents the sum of number of protons and number of neutrons.
Atomic mass = Number of protons + number of neutrons
Hope this helps!
Answer:
Option B.
Explanation:
As any reaction of combustion, the O₂ is a reactant and the products are CO₂ and H₂O. Combustion reaction for ethane is:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
So 2 moles of ethane react with 7 moles of oxygen to make 4 moles of dioxide and 6 moles of water.
Then 2 moles of ethane will produce 4 moles of CO₂
