<span>The two elements that constitute almost three fourths of the earth's solid surface are oxygen and silicon. Oxygen accounts for 46.6 percent of the Earth's crust, while silicon is 27.7 percent. The next more plentiful element on the Earth's crust is Aluminum.</span>
The crust?? I gues brcause idk if thusnis correct sry
Always use least amount of sig figs possible. So this 9.7 would be (answer): 2 sig figs
PH=-log[H⁺]
pH=-log(1.87×10⁻¹³)
pH=12.72
I hope this helps. Let me know if anything is unclear.