True or False: The % abundance of an element's isotopes always totals 100%.

When light strikes a plane mirror, images form in locations where light does not actually reach. it only appears to the observer as though the light were coming from this position. what type of image is formed?

Which feature do highland climates have that lower elevation areas do not?

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange