Answer:
A: Helium or Hydrogen
Explanation:
Terrestrial planets are the 4 inner most planets of the solar system which are mercury, venus, earth, Mars, while the giant planets are the 4 outer most which are Jupiter, Saturn, Uranus and Neptune.
Now, these outer most ones are the surface ones and are surrounded primarily by layers of hydrogen and helium gases.
The trend of ionization energy in the periodic table is decreasing from right to left and from top to bottom. In this case, we are given with elements <span>K, Ca, Ge, Se, Br, Kr and see the periodic table to check the trend. The answer from highest to lowest Kr, Br, Se, Ge, Ca, and K</span>
Hot liquid rock comes in contact with Earth´s cold crust
Yes it is polluting the river with everything the manufaturing plant gives off such as the chemicals released in the air
