A neutral atom of potassium (K) has an average mass of 39 amu and 19 electrons. How many neutrons does it have? 10
19
20
58
Explain.

Why does karst topography exist in some geographic location? a. few climates have enough oxygen b. most regions have rock layers other than limestone c. in most regions, the soil is too thin d. the water is too acidic enough in most places