its 40
I just took the test right now to get this answer
<em>answer:</em><em> </em><em>option </em><em>d </em><em>(</em><em>2</em><em>×</em><em>m</em><em>o</em><em>l</em><em>a</em><em>r</em><em> </em><em>mass </em><em>of </em><em>H </em><em>+</em><em>2</em><em>×</em><em>m</em><em>o</em><em>l</em><em>a</em><em>r</em><em> </em><em>mass </em><em>of </em><em>O</em>
<em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em>
Usually (ignoring transition metals, as they kinda get trickier), the element's valency can be found out by its group (column) number. Usually, we ignore the transition metal block while counting these columns, so Aluminium is in group 3, for example. Since Aluminium is in group 3, it has 3 valence electrons.
<span><u><em>Answer:</em></u>
combustion reaction
<u><em>Explanation:</em></u>
In chemistry, a <u>combustion reaction</u> is defined as a reaction between an oxidant and any compound that leads to the production of another compound along with a huge amount of heat.
<u>Now, let's check the reaction given:</u>
C</span>₃H₈<span> + 5 O</span>₂<span> --> 3 CO</span>₂<span> + 4 H</span>₂O<span>
<u>The oxidant</u> is oxygen gas
<u>The compound reacting</u> is propane
<u>The compound produced</u> is carbon dioxide along with water vapor and heat
Therefore, the given reaction is a combustion reaction
Hope this helps :)</span>
