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: Among the listed substances
is the molecular compound.
Explanation:
A chemical compound formed by the chemical combination of two or more non-metals is called a molecular compound or covalent compound.
For example, Xe and Cl are non-metals. The compound formed by them is
which is a molecular compound.
A molecular compound is formed by sharing of atoms between the combining atoms.
Whereas NaF,
and CaO are all ionic compounds as they are formed by chemical combination of a metal and a non-metal.
Thus, we can conclude that among the listed substances
is the molecular compound.
Answer:
30, 50
Explanation:
Hello,
In this since an element's atomic number is equal to the number of protons in its atom, we can infer that selenium's atomic number is 30. Moreover, due to the fact the the neutrons are equal to the atomic mass minus the atomic number or the number of protons, by knowing the number of neutrons we compute the atomic as follows:

Thus, answer is 30, 50.
Best regards.
Answer:
Explanation: Q1 = mc(ice) ΔT (ice warms)
Q2 = ms (ice melts)
Q3 = mc((water) ΔT (water warms)
Q4 = mr (water boils)
Q5 = mc(vapour)ΔT