Of the reactions involved in the photodecomposition of ozone (shown below), which are photochemical? 1. o2 (g) + hν → o (g) + o (g) 2. o (g) + o2 (g) + m (g) → o3 (g) + m* (g) 3. o3 (g) + hν → o2 (g) + o (g) 4. o (g) + o (g) + m (g) → o2 (g) + m* (g)