A, the independent variable is the thing you change, the dependent is the variable you measure.
that its a chain of the environment keeping balance
Answer:
B
Explanation:
When a mass of air is heated it becomes less dense. This is why a hot air balloon rises in the atmosphere. It is also the same reason why hot air rises and the moisture in it condenses to form clouds. The cooler less dense air mass moves downards (in some convection currents fashion) in to replace the hot rising air.
I can help with the first one and third for you.
Symbol | atomic # | Mass of # | # of Protons | # of electrons | # of neutrons
Na | 11 | 23 (when rounded) | 11 | 11 | 12
Sr | 38 | 88 (when rounded) | 38 | 38 | 50
(sorry if this didn't help)