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!
True yes TRUE
Science may also be defined as the study of surroundings
I<span>n </span>direct current<span> (</span>DC), the electric charge (current<span>) only flows in one direction. Electric charge in </span>alternating current<span> (</span>AC<span>), on the other hand, changes direction periodically. The voltage in </span>AC<span> circuits also periodically reverses because the </span>current<span> changes direction.</span>
We have no idea. There are probably many things involved ... the planet's mass,
the availability of small bodies in the neighborhood that can be captured, etc.
