Antoine Lavoisier named this compound and its respective element after discovering its importance in combustion.
When Vaska's complex is exposed to this molecule, it forms an adduct and changes color from yellow to orange. The presence of only one electron in each of the highest-occupied pi-star orbitals in this molecule's molecular orbital diagram explains why its liquid form is (*) paramagnetic. This molecule is the third heaviest of the diatomic gaseous elements, and a glowing splint is usually used to test for its presence. Antoine Lavoisier named this compound and its respective element after discovering its importance in combustion. For 10 points, name this gas, the second most common element in air after nitrogen.
When Vaska's complex is exposed to this molecule, it forms an adduct and changes color from yellow to orange.
diatomic oxygen (accept molecular oxygen and dioxygen and O2)