Please help :)
1: Catalysts lower the activation energy of chemical reactions. How does this benefit the environment?

2: Chlorine free radicals are produced in the upper atmosphere when ultraviolet radiation interacts with chlorofluorocarbons (CHCs). The free radicals catalyze the conversion of ozone to oxygen. How is this catalysis harmful to humans

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

Adepositional also feature that forms where a stream enters a lake or an ocean is a

Which property of a rock remains unchanged by mechanical weathering? a. total surface area b. size and shape c. mineral composition d. sharpness