Sometimes negative sometimes positive, your answer is B!
Answer:
Explanation: The strengths of the inter molecular forces varies as follows -

The normal boiling point of CSe2 is 125°C and that of CS2 is 116°C, which explains the trend that as we move down the group, the boiling point of e compound increases as the size increases.
This usually happens because larger and heavier atoms have a tendency to exhibit greater inter molecular strengths due to the increase in size . As the size increases, the valence shell electrons move far away from the nucleus, thus has a greater tendency to attract the temporary dipoles.
And larger the inter molecular forces, more tightly the electrons will be held to each other and thus more thermal energy would be required to break the bonds between them.
Answer:
The correct row is B.
Explanation:
The formation of the magnesium ion, Mg²⁺, comes from the removal of 2 electrons from the valence shell of the magnesium atom.<em> </em>Since the remotion is of electrons, the nucleus of the atom remains the same, so the number of protons and the number of neutrons does not change.<em> </em>
If the number of proton change, then the atom also change, since the identity of an atom is related to the atomic number which is the same to the proton number.
Now, if the number of neutrons changes, then we would be in the presence of an isotope of the magnesium atom.
Therefore, the correct row is B.
I hope it helps you!