Fountains often used to cool enclosed courtyards of houses in hot and dry countries. How does a fountain help lower the temperature of a
courtyard? (Hint: evaporation requires energy) *

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.