-<u><em>Oxygen</em></u>
According to Google these are the percentages of the <em>Earths Atmosphere</em>
<em>1</em> 78% - Nitrogen
<u>2</u> 21% - Oxygen
<em>3</em> 0.9% - Argon
<em>4 </em>0.3 - Carbon Dioxide with very small percentage of other elements.
So it contains three protons and four neutrons
Answer:
Ne
Explanation:
Atomic number of Ne is 10.
Electronic configuration of Ne:
Octet of Ne is complete . Element having complete octet are stable and behave ideal gas.
and 
are reactive and hence, does not behave as ideal gas.
When a fuel burns, it combines with oxygen int the air and changes into the substances water and carbon dioxide. That's how Flammability is a chemical property.
<span>1s^22s^22p^63s^1 i think</span>
