An astronomer observes an asteroid in the solar system. He notes that the asteroid is three times farther from the Sun than Eart
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Answer:
Z* = 3.55
Explanation:
Slater rule says that:
Z*= Z - S
Z* be the nuclear effective charge
Z is the nuclear charge
S is the shielding constant
First we write the electronic configuration of platinum:
The first Slater rule says that we need to group:
The second rule says that the electrons to the right are not shielding, but we are going to solve the exercise for the last level (6s), so we don't have electrons to the right.
For the third rule we have two considerations, if is ns or np and if is nd or nf:
For our case, we have an electro that is in ns, so the rule says that
-electrons within same group shield 0.35, except the 1s which shield 0.30
-electrons within the n-1 group shield 0.85
-electrons within the n-2 or lower groups shield 1.00
Now we can proceed with the calculation:
The first consideration in the third rule does not apply as we only have one electron on this level.
The second consideration will be as follow for the level 5, where we have 17 electrons.
Finally the third consideration will be for levels 1, 2, 3 and 4, where we have 14 for 4f, 10 for 4d, 8 for 4s and 4p, 10 for 3d, 8 for 3s and 3p, 8 for 2s and 2p and finally 2 for 1s, which gives 60 electrons.
So the result for S=(60*1.00 + 17*0.85) = 74.45
And the equation is: Z* = 78 - 74.45
So Z* = 3.55
Answer:
- <u><em>Sodium chloride</em></u>
- See the graph attached
Explanation:
The attached graph with a green and a red arrow facilitates the understanding of this explanation.
To read the <em>solubility </em>on the <em>graph</em>, you can start with the temperature, on the x-axis.
The red vertical arrow shows how, departing from the <em>40ºC temperature</em> on the x-axis, you intersect the<em> solutibility curve </em>of sodium chloride at a height (y-axis) corresponding to <em>60 g/100cm³ of water</em> (follow the green horizontal arrow).
Hence, <em>sodium chloride is the salt that can dissolve at a concentration of about 60g/100cm³ of water at 40ºC.</em>
