How to balance this equation KClO4 → KCl + ?O2(g) and what type of reaction occurs?

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the boiling of water, and explain your predictions. how does temperature affect the spontaneity of this process?

Which fact represents evidence for the big bang theory?