The traditional calcium atom has twenty protons and twenty electrons making it neutral.
The calcium in the pic is a calcium ion so the number of protons and electrons are not equivalent.
Since it's 2+ that means the ion is positively charged and for that to happen electrons are away.
So 20-2=18
There are 18 electrons
Answer:
Water's boiling point is higher than acetone's one due to the stronger intermolecular forces it has in liquid phase.
Explanation:
Hello.
In this case, since no options are given we can infer from the statement that due to water's higher boiling point than acetone we can conclude that when they are in liquid state, water has stronger intermolecular forces which allow its particles to be held in a stronger way in comparison to the acetone's molecules, for that reason, more energy will be required in order to separate them and promote the boiling process, which is attained via increasing the temperature. Besides, less energy will be required for the separation of the acetone's molecules in order to boil it when liquid, therefore, a lower temperature is required.
In such a way, we can sum up that water's boiling point is higher than acetone's one due to the stronger intermolecular forces it has in liquid phase.
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Answer:
Equilibrium concentrations of the gases are



Explanation:
We are given that for the equilibrium

Temperature, 
Initial concentration of



We have to find the equilibrium concentration of gases.
After certain time
2x number of moles of reactant reduced and form product
Concentration of



At equilibrium
Equilibrium constant
![K_c=\frac{product}{Reactant}=\frac{[H_2]^2[S_2]}{[H_2S]^2}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7Bproduct%7D%7BReactant%7D%3D%5Cfrac%7B%5BH_2%5D%5E2%5BS_2%5D%7D%7B%5BH_2S%5D%5E2%7D)
Substitute the values



By solving we get

Now, equilibrium concentration of gases



Answer:
24.7 amu
Explanation:
An isotope is when an element can have different number of neutrons but they have same number of protons.
In order to calculate the average atomic mass with the given information do the following operations:
First change de percentages to fractional numbers, divide by 100.
I like to make a table, to organize all data and I believe is easier to understand.
65/100 = 0.65
35/100 = 0.35
% fraction
65.0 0.65
35.0 0.35
total100.0 1
Now multiply each mass with their corresponding fraction
24 (0.65) = 15.6
26 (0.35) = 9.1
% fraction uma uma
65.0 0.65 24 15.6
35.0 0.35 26 9.1
total100.0 1 24.7
Finally you add the resulting mass and the units will be in uma.
15.6+9.1 = 24.7
Therefore the average atomic mass of this element will be 24.7 uma.
Check the table in the document attached
C.Dissolve because its another word for soluble