The "sub shells" are the orientations and shapes for your orbitals, going in order by Shells are a collection of subshells with the same principle quantum number, and subshells are a collection of orbitals with the same principle quantum number and angular momentum quantum number. Hope this helps :)
<span><span>Yes.
An element that is highly electronegative pulls more on the electrons
in a bond, such as oxygen in H20. This creates a polar bond, where
there is a small negative charge on the oxygen, and a small positive
charge in between the hydrogens.
</span>Credit goes to "Erin M" answered on yahoo answers a decade ago.
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Answer:
<h2>B i have to search it like 23 hours to find it but Thank you for sharing your question :)</h2>
The early precambrian atmosphere consisted primarily of nitrogen and carbon dioxide with almost no oxygen.
<span>Today, the atmosphere contains about 20% oxygen, less carbon dioxide and similar amounts of nitrogen. </span>
<span>Photosynthetic green-leaf plants and trees are largely responsible for the change, converting carbon dioxide to oxygen.</span>
