Thermal energy travels<span> by conduction, convection, and radiation. It occurs when a cooler and warmer object touches each other. </span>
Answer:
if the heat of reaction is positive, the reaction is said to be endothermic; if negative, exothermic.
Explanation:
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i am so sorry if this is the wrong answer
Answer:
<em>Your</em><em> </em><em>Answer</em><em> </em><em>is</em><em> </em><em>Option</em><em> </em><em>A</em><em> </em><em>that</em><em> </em><em>is</em><em> </em><em>Gas</em><em>.</em>
Answer:
do it by yourself 6637373
Answer:- 3. 
and 
Explanations:- An empirical formula is the simplest whole number ratio of atoms of each element present in the molecule/compound.
For example, the molecular formula of benzene is 
. The ratio of C to H in it is 6:6 that could be simplified to 1:1. So, an empirical formula of benzene is CH.
In the first pair, the ratio of C to H in first molecule is 2:4 that could be simplified to 1:2 and the empirical formula is 
. In second molecule the ratio of C to H is 6:6 and it could be simplified to 1:1. and the empirical formula is CH. Empirical formulas are different for both the molecules of first pair and so it is not the right choice.
In second pair, C to H ratio in first molecule is 1:2, so the empirical formula is . The C to H ratio for second molecule is 1:4, so the empirical formula is 
. Here also, the empirical formulas are not same and hence it is also not the right choice.
In third pair, C to H ratio in first molecule is 1:3, so the empirical formula is . In second molecule the C to H ratio is 2:6 and it is simplified to 1:3. So, the empirical formula for this one is also . Hence. this is the correct choice.
In fourth pair, first molecule empirical formula is CH. Second molecule has 2:4 that is 1:2 mole ratio of C to H and so its empirical formula is . As the empirical formulas are different, it is not the right choice.
So, the only and only correct pair is the third one. 3. and
