After one half life, 188mg
46.9 mg of Ba-142
After 5 half lives
After 106 minutes
20 half lives , only 0.000358 mg remains
Hope this helps
Atoms have equal numbers of protons and electrons. So it have 40 protons.
The molar mass and the mass of the substance give the moles of the substance. The 10-gram sample of neon (Ne) has the fewest atoms. Thus, option b is correct.
<h3>What are moles?</h3>
Moles of the substance are the ratio of the molar mass and the mass of the substance. The moles of each atom with respect to the Avagadro's number (Nₐ) is given as,
Moles = mass ÷ molar mass
- Moles of carbon (C) = 10 ÷ 12
= 0.83 Nₐ atoms
- Moles of neon (Ne) = 10 ÷ 20
= 0.5 Nₐ atoms
- Moles of fluorine (F) = 10 ÷ 19
= 0.52 Nₐ atoms
- Moles of nitrogen (N) = 10 ÷ 14
= 0.7 Nₐ atoms
- Moles of oxygen (O) = 10 ÷ 16
= 0.63 Nₐ atoms
Therefore, option b. 10 gm neon has the fewest atoms.
Learn more about moles here:
brainly.com/question/11884840
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Answer:
895.8g/mol
Explanation:
Hello, here the solution:
Consider the formula for the boiling-point elevation:
We solve for the molality of the solute:
By knowing the mass of the diethyl ether (271.8 g =0.2718kg) and that 11.20g of the solute were dissolved, the molecular mass is given by:
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