Element A is more reactive. Take Fluorine for example. Since its in group 17, it needs one more electron to have an octet. Compared with carbon, group 14 with 4 valence electrons, Fluorine wants and is able to get an electron much more easily.
It's Co just look at the periodic table
evaporation systems allow for an endless source of water. you can grab cups of water straight from the sea or even a lake. the use of evaporation allows for you to drink water thats even healthier than getting it from a cloud and it will leave all of the bad parts that used to be in the water in the first container you pour into. this system is most useful in hot climates such as places near the equator.
Sulfur’s Bohr diagram 1 S^2 2S^2 2P^6 3S^2 3S^4. Like Oxygen, needs 2 electrons on outer ring to become stable.