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:
Here's what I get.
Explanation:
The Antoine equation is
A = 13.7819
B = 2726.81
C = 217.572
I did the calculations and the plots in Excel.
Figure 1 shows the calculations, Figure 2 is the linear plot, and Figure 3 is the log plot.
We first assume that the gas is ideal which is a safe assumption to approximate the answer to the problem. Then we need to know the ideal gas equation and that is:
PV=nRT
where
P- pressure
V- volume
n-number of moles-
R- ideal gas constant
T-temperature.
Since we know that P, T and V are constant, rearranging the equation would lead to:
P/TR = n/V or the ratio of the moles of gas and volume is constant.
(3moles)/2L = (3+x)/4L
where
x is the additional moles.
Solving for x = 3 moles.
Answer:
The 3rd answer down.
Na²O (sodium oxide) will be a base when exposed to water H²O
Explanation:
Sodium Oxide Na²O, will become Sodium Hydroxide after being exposed to water (at 80% I believe).
The oxygen ion in Na²O has 2 extra electrons which makes it highly charged and very attractive to hydrogen ions. The attraction is so strong that when Na²O comes in contact with H²O, the O(-2) strips off a hydrogen from water, forming 2 x OH ions which of course are still strongly basic.
The correct answer is B(OH)3 <AI(OH)3 < In(OH)3.
The metallic character of the group 1 elements first increases from Boron to Aluminium, then decreases from Aluminium to Thallium because of high ionization Enthalpy. Also, the larger size of the ion, the lesser is the ionization of Enthalpy.
Basic nature of the hydroxides of group 13 increases on moving down the group as the electro-positive character of elements increases.
Therefore, the correct order of increasing aqueous basicity is as follows:
B(OH)3 <AI(OH)3 < In(OH)3
What is the basic nature of group 13?
The metallic charecter of the elements affects their fundamental characteristics. The basicity rises as the metallic character does, and vice versa. Therefore, as we move lower in any given group, the atomic radius of the elements increases. Higher radii indicate that it would become increasingly challenging for the nucleus to rule over the electrons in the valency shell. Consequently, there will be a greater inclination for electron release. As a result, the metallic properties will improve, increasing the basicity of the oxides. Therefore, it follows that the basicity of the oxides would rise as we go down in a group.
To learn more about hydroxides refer the link:
brainly.com/question/10134219
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