Answer:
Explanation:
The Ce metal has electronic configuration as follows
[Xe] 4f¹5d¹6s²
After losing 4 electrons , it gains noble gas configuration ,. So Ce ⁺⁴ is stable.
Eu has electronic configuration as follows
[ Xe ] 4 f ⁷6s²
[ Xe ] 4 f ⁷
Its outermost orbit contains 2 electrons so Eu²⁺ is stable. Its +3 oxidation state is also stable.
Ce⁺²
Answer:
mole fraction hexane 0.64
Explanation:
We know from Raoult's law of partial pressures that for a binary mixture, the vapor pressure above solution is the sum of the partial pressures of each gas:
P total = P(A) + P(B)
Also the partial pressure of a component is the product of its mole fraction , X, times its pure vapor pressure:
Ptotal = X (A)Pº(A) + X (B)Pº(B)
Since for solution of two components the mole fractions add to one, we now have all the information required to compute the answer.
250 torr = X(hexane)151 torr + ( 1 - X(hexane) )425 torr
250 = 151X(hexane) + 425 - 425 X(hexane)
274 X(hexane) = 175
X(hexane) = 1 -0.6 = 0.64
The chemical name is ferric oxide or iron (III) oxide or hematite. We can found it naturaly as a magnetite, mineral.
Answer: The answer is 6.78 grams.
Explanation: The equation used for solving this type of problems is:
where, 
is the initial amount of radioactive substance, N is the remaining amount and n is the number of half lives.
Number of half lives is calculated on dividing the given time by the half life.
n = time/half life
Time is given as 48.0 hours and the half life is given as 4.536 days. let's make the units same and for this let's convert the half life from days to hours.
= 108.864 hours
So, 
= 0.441
Since 5.00 g is the required amount when the radioactive substance is delivered to the scientist, it would be the final amount that is N. We need to calculate the initial amount. Let's plug in the values in the equation:
= 6.78 g
So, 6.78 g of the radioactive substance needs to be ordered.
