A burning splint will burn more vigorously in pure oxygen than in air because <span>oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air.
Oxygen concentration in air is approximately 20%, the rest of are nitrogen, carbon dioxide and other gases. Oxygen is oxidazing reactant, that means oxygen give electrons in chemical reactions.
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Answer:

Explanation:
The atomic number (Z) of copper is 29 and this isotope has an atomic mass (A) of 70.
The general symbol for an isotope E is
.
The atomic number is a left subscript, and the atomic mass is a left superscript.

<em>malai</em><em> </em><em>aaudaina</em><em> </em><em>aati</em><em> </em><em>jabo</em><em> </em><em>tapai</em><em> </em>
<em>lai</em><em> </em><em>aaudaina</em><em> </em>