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:
d)
Explanation:
the only one that makes sense
Answer:
1. 
2. 
3. 
Explanation:
Given:
- mass of slinky,

- length of slinky,

- amplitude of wave pulse,

- time taken by the wave pulse to travel down the length,

- frequency of wave pulse,

1.



2.
<em>Now, we find the linear mass density of the slinky.</em>


We have the relation involving the tension force as:




3.
We have the relation for wavelength as:



This can be seen through the fact that Aksionov has the ability to seek his own justice many times throughout the story, yet does not take it
The answer would be E7. Galaxies categorized as E0 look to
be nearly perfect, while those registered as E7 seem much extended than they
are widespread. It is worth noting, though, that a galaxy's look is connected
to how it lies on the sky when viewed from Earth. An E7 galaxy is very long and
thin or the flattest of them all.