<span>Because there is a permanent dipole between the Br and Cl atom. The Cl atom has a higher electronegativity, so it will tend to pull the "shared" electrons formed in the bond to its pole, creating a permanent dipole and partial electron deficiency on the bromine atom.</span>
The third question requires you to solve for the weight of sodium (Na) and weight of Chloride (Cl) from the calculated moles of each element Na, and Cl.
So, you need to multiply the calculated moles of Na with its molar mass (23 g/ mol) to get the answer for Na. And multiply the calculated moles of Cl with its molar mass (35.45 g/mol) to get the answer for Cl.
Answer: Isotopes of an atom are different because they have different atomic masses and different number of neutrons within their nucleus. They are the same since they will always have the same atomic number/number of protons in their nucleus.
Explanation: