Periodic table is confusing ;-; plz helppp Okay so the group number is supposed to equal to the valence electrons of the elements in said group. But, for example fluorine, has 7 valence electrons even though it's in group 17. I know it's unlikely for a non-metal to have 17 valence electrons, but still I'm quite confused??? Is there some special way to read groups I missed??

Which statement explains which thermometer is more appropriate to measure the temperature of a liquid at 43.6 degrees celsius a) thermometer a, because it measures temperature more accurately than thermometer b b) thermometer b, because it measures temperature more accurately than thermometer a c) thermometer a, because it measures temperature more precisely than thermometer b d) thermometer b, because it measures temperature more precisely than thermometer a