First, you convert liters to moles.
Usually you have to go to grams but this is STP.
Get moles directly by dividing the 4 by STP (22.4)
About
or 0.18 moles whichever your teacher prefers
ZnO
is the answer for what is the chemical formula for zinc?
Option 4. ratio of electrons to protons
Isotope that has atomic number of 82 is stable. An element that has an atomic number ∠82 more stable except Tc and Pm. Also there is the concept that isotopes consisting a combination of even-even,even-odd,odd-even, and odd-odd are all stable. Many isotopes with no magic numbers of nucleons are stable
Reactivity of Group 1 and 2 elements increases as you go down the periodic table. So sodium is more reactive than lithium. Sodium will react with oxygen forming Na2O (sodium oxide). Lithium forms lithium oxide (Li2O).