Which element has an ion that is smaller than an ion of calcium? potassium strontium cesium magnesium

Which element would mostly likely have an electron affinity measuring closest to zero

Which is an example of the practical pursuit of alchemy? a. forming perfect substances. b. transforming base metals. c. developing metalworking techniques. d. linking spiritual characteristics with material substances.

The missing component to the table to the right or indicated with orange letters complete the table by filling in the corresponding numbers or symbols