It contains neutrons, which have no charge. Protons which have a positive charge and electrons which have a negative charge. These are all called subatomic particles
Answer:
6.25%
Explanation:
Given data:
Half life of lutetium-117 = 6.75 days
Percentage remaining after 27 days = ?
Solution;
Number of half lives = Time elapsed / half life
Number of half lives = 27 days / 6.75 days
Number of half lives = 4
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At 3rd half life = 25%/2 = 12.5%
At 4th half life = 12.5%/2 = 6.25%
Answer:
mole fraction of NaCl = 0.03145.
mole fraction of water = 0.9686.
Explanation:
- Mole fraction is an expression of the concentration of a solution or mixture.
- It is equal to the moles of one component divided by the total moles in the solution or mixture.
- The summation of mole fraction of all mixture components = 1.
mole fraction of NaCl = (no. of moles of NaCl) / (total no. of moles).
<em>no. of moles of NaCl = mass/molar mass </em>= (6.87 g)/(58.44 g/mol) = 0.1176 mol.
<em>no. of moles of water = mass/molar mass</em> = (65.2 g)/(18.0 g/mol) = <em>3.622 mol.</em>
<em></em>
∴ mole fraction of NaCl = (no. of moles of NaCl) / (total no. of moles) = (0.1176 mol)/(0.1176 mol + 3.622 mol) = 0.03145.
<em>∵ mole fraction of NaCl + mole fraction of water = 1.0.</em>
∴ mole fraction of water = 1.0 - mole fraction of NaCl = 1.0 - 0.03145 = 0.9686.
<span>(P1/T1) = (P2/T2)
T must be in kelvin first!</span>
