if we approximate the atmosphere to be 79% nitrogen (n2) and 21% oxygen (o2) by volume, calculate the density of air (kg/m3) at stp conditions (0oc, 1 atm). hint: 1 mole of gas occupies 22.414 l at stp.

i belive it is water

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.