Mg + 2HCl = H₂ + MgCl₂
n(HCl)=c(HCl)v(HCl)
n(H₂)=n(HCl)/2=c(HCl)v(HCl)/2
n(H₂)=3.0mol/L*0.2500L/2=0.375 mol≈0.38 mol
Answer: THE ANSWER IS OZONE WEEEE a layer in the earth's stratosphere at an altitude of about 6.2 miles (10 km) containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun.
Explanation:
It takes the Earth 24 hours to rotate on its axis and this rotation is what causes there to be days and nights.