Final answer:
The balanced chemical equation for the reaction between lithium and oxygen to form lithium oxide is 4Li + O₂ → 2Li₂O.
Step-by-step explanation:
Lithium and oxygen react to form lithium oxide, and the balanced equation for this reaction is: 4Li + O₂ → 2Li₂O. The lithium atom has a +1 charge, and the oxygen atom as part of O₂ gas has a -2 charge. The crisscross method tells us that we need two lithium ions to balance out the charge of one oxide ion, resulting in the formula Li₂O for lithium oxide. Consequently, to balance the chemical equation, we need four lithium atoms reacting with one molecule of oxygen gas to yield two units of lithium oxide.
Remember that balancing chemical equations ensures conservation of mass, meaning the number of atoms of each element must be the same on both sides of the equation. It also involves molar amounts, indicating that stoichiometric coefficients refer to moles of substances in the reaction.