Explanation:
Solar panels are visible on roof tops on homes and businesses. Solar thermal technology transforms solar energy to heat, which is then used to heat homes, businesses and even swimming pools, or transformed again into electricity.
It’s “a”, frequency because the sound waves will cause vibrations in object close by
I think it's D- Number of neutrons
The molarity of HCL is 71mL, the H3O+ 49g, and the pH is 12.