Answer:
Hydrogen and helium compounds.
Explanation:
We know that the solar System was formed around <u>4.6 billion years ago, </u>due to the gravitational collapse of a giant interstellar molecular cloud.
This cloud is a type of interstellar cloud and its density and size permit the formation of molecules, most commonly molecular hydrogen.
Therefore the principal substances were found before planets began to form are hydrogen and helium compounds, besides Rocks, metals, most of them in gaseous form.
I hope it helps you!
Answer:
B)8
Explanation:
In the first energy level you can have, at most, 2. Every energy level after that wants to have 8 electrons. Valence electrons I believe.
Hope this helps, have a nice day! (^-^)
The answer is that FRICTION PRODUCES HEAT.
Answer:
The SI units of A, B and C are :
Explanation:
The position x, in meters, of an object is given by the equation:
Where
t is time in seconds
We know that the unit of x is meters, such that the units of A, Bt and 
must be meters. So,
So, the SI units of A, B and C are :
So, the correct option is (B).
