Effective nuclear charge is the charge felt by valence electrons of multi-electron atom taking into consideration the number of shielding electrons that surround the nucleus.
To calculate Z eff for electron we use this formula :
Z eff = Z - S where Z is the number of protons in nucleus and S is the average amount of electron density between the nucleus and electron in consideration
so Z eff = 17 - 10 (core electrons) = 7
So the correct answer is C
the answer to this question is B.
Answer:
B. honey dissolving in tea
Explanation:
Number of electrons or protons present in a neutral atom is called atomic number. It is represented by Z.
So what we know:
-Atomic Mass = Protons + Neutrons
-Atomic Number is the number of protons
Magnesium's atomic number is 12, so the natural occurring isotope for magnesium is Mg-12 (12 protons and 12 neutrons). Added up we have an atomic mass of 24 amu. Which means if we added one neutron in Mg-13, our atomic mass would be 25 amu.
We can use the equation:
(amu of isotope 1)x + (amu of isotop 2)(x-1) = Average atomic mass
where isotope 1 is the fractional abundance we're solving for.
Plugged in it looks like this:
24x + 25(1-x) = 24.3
Now to solve for x:
24x + 25 - 25x = 24.3
-x + 25 = 24.3
-x = -.7
x = .7
So in this case, the fractional abundance of Mg-12 would be .7, or 70%.<span />
