>>3871692Correct.
I imagine they want you to get to that answer by using the periodic table and knowing the electronegativity trend. In which fluorine (at the top right) is the most electronegative at ~4, and francium (bottom left) is the least at ~
0.7.So as you move up and to the right, electronegativity increases.
Electronegativity, being an indicator of the strength of an atom's electron's ability to attract positive charges (other atoms), is used to gauge bond strength. The greater the difference in electronegativity between two atoms, the greatets the bond strength is, and the more energy it'd take to break that bond.
LiF has a greatest difference than BaCl2, so the LiF bond is stronger and requires more energy to break.
You can verify that by looking up the heat of formation for both LiF and BaCl2. LiF has a heat of formation of -1017 kJ/mol and BaCl2 is -799 kJ/mol. Essentially the heat of formation is how much energy is exchanged when a compound is formed. When LiF is formed from Li+ and F-, it releases 1017 kJ per mol to form LiF. It's the same in reverse, to break LiF, 1017 kJ/mol must be supplied, that's the energy required to break LiF.
I think the question might throw some people off because LiF has one ionic bond (only 2 atoms in the molecule) and BaCl2 has two ionic bonds (3 atoms in the molecule). Which is an interesting thing to think about and I'm not entirely sure why it's less energy to break BaCl2's two ionic bonds than it is to break a single LiF ionic bond even though the electronegativity difference isn't that great.
But the answer that LiF takes more energy to break than BaCl2 is supported by the heat of formation for both, and by the periodic table electronegativity trend (which is the method I assume they want you to use), so I hope that helps you.
