<span>The effective nuclear charge of an atom = total electrons - inner electrons
For O, ENC = 8 - 2 = 6
For Li, ENC = 3 - 2 = 1
For C, ENC = 6 - 2 = 4
The electrons in O experience the greatest effective nuclear charge and that is why O is smaller than C (which is smaller than Li).</span>
Answer:
37.8g/ 10.81g/mol = 3.4968...moles
Do we get multiple choice
Answer:
the energy of the third excited rotational state 
Explanation:
Given that :
hydrogen chloride (HCl) molecule has an intermolecular separation of 127 pm
Assume the atomic isotopes that make up the molecule are hydrogen-1 (protium) and chlorine-35.
Thus; the reduced mass μ = 
μ = 
μ = 
∵ 1 μ = 1.66 × 10⁻²⁷ kg
μ = 
μ = 1.6139 × 10⁻²⁷ kg

The rotational level Energy can be expressed by the equation:

where ;
J = 3 ( i.e third excited state) &




We know that :
1 J = 



Answer:
E - Be and O
A - Mg and N
E - Li and Br
F - Ba and Cl
B - Rb and O
Explanation:
Be and O
Be is a metal that loses 2 e⁻ to form Be²⁺ and O is a nonmetal that gains 2 e⁻ to form O²⁻. For the ionic compound to be neutral, it must have the form BeO (E-MX).
Mg and N
Mg is a metal that loses 2 e⁻ to form Mg²⁺ and N is a nonmetal that gains 3 e⁻ to form O³⁻. For the ionic compound to be neutral, it must have the form Mg₃N₂ (A-M₃X₂).
Li and Br
Li is a metal that loses 1 e⁻ to form Li⁺ and Br is a nonmetal that gains 1 e⁻ to form Br⁻. For the ionic compound to be neutral, it must have the form LiBr (E-MX).
Ba and Cl
Ba is a metal that loses 2 e⁻ to form Ba²⁺ and Cl is a nonmetal that gains 1 e⁻ to form Cl⁻. For the ionic compound to be neutral, it must have the form BaCl₂ (F-MX₂).
Rb and O
Rb is a metal that loses 1 e⁻ to form Rb⁺ and O is a nonmetal that gains 2 e⁻ to form O²⁻. For the ionic compound to be neutral, it must have the form Rb₂O (B-M₂X).