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Solution: Using the periodic table to guide you, predict the chemical ...

Question

Using the periodic table to guide you, predict the chemical formula and name of the compound formed by the following elements: (d) K and S

Video Transcript

Hey guys, so here we have to write the chemical formula and give the chemical name for the compound. So here we have a compound that's going to form between potassium and sulphur. The first step is to figure out the charges of each. Potassium is located in group 1A so the charge is going to be +1 meaning that we need to lose 1 electron to reach the noble gas configuration so this becomes K+.

Sulphur on the other hand is in group 6A so it needs to gain 2 electrons to gain the noble gas configuration so this is going to be S2-. Now to create the chemical formula we look at the charges. The charges are not the same so they do not cancel each other out. Since they do not cancel each other out, that means that the values are going to criss-cross. So the 2 from sulphur is going to go to potassium and the 1 from potassium is going to go to sulphur. So they criss-cross. So the chemical formula becomes K2S.

Now to write out the formula, the first atom is going to keep its original name so it's going to be potassium and the second atom keeps the base name but the ending changes to I D E. Now the base name for sulphur is going to be sulph and the ending becomes I D E. So the full answer is potassium sulphide. Alright guys, see you soon.