I don't understand this problem, can anyone help clarify it for me? For which of the following reactions will a decrease in pressure shift the equilibrium to the left?

chemistry sucks a**

explanation:

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

i think its 100.

hope this !