The new combination is called a mixture.
In mixtures, since the substances are not chemically combined together, they still remain their own physical and chemical properties, and can be separated by simple physical methods such as filtration or distillation.
On the other hand, if the two or more substances are combined where they get new properties, the new combination will be called a compound. They cannot be separated by physical methods, but chemical methods such as heating or electrolysis.
Answer: 
Explanation:
Given
Mass of water in the sample is 
Temperature changes from 
to 
Change in temperature is 
We know, specific heat of water is 
Heat absorbed is given by
Thus, water absorbs of heat from hot plate.
Yes, car oil can degrade carbon fiber
To balance any redox equation, first divide the reaction into two half reactions, and balance the atom whose oxidation number is changing:
<span>NO2 --> NH3 </span>
<span>H2 --> H2O </span>
<span>Next, balance oxygens by adding H2O where needed, and then balance hydrogen by adding H+: </span>
<span>NO2 --> NH3 + 2 H2O </span>
<span>H2O + H2 --> H2O </span>
<span>7 H+ + NO2 --> NH3 + 2 H2O </span>
<span>H2O + H2 --> H2O + 2 H+ </span>
<span>Next, balance charges by adding electrons (e-): </span>
<span>7 H+ + NO2 + 7 e- --> NH3 + 2 H2O </span>
<span>H2O + H2 --> H2O + 2 H+ + 2 e- </span>
<span>Now, multiply one or both equations by small numbers to make the number of electrons the same in the two half reactions. In this case, multiply the top equation by 2 and the bottom one by 7 to give you 14 electrons in each half reaction: </span>
<span>14 H+ + 2 NO2 + 14 e- --> 2 NH3 + 4 H2O </span>
<span>7 H2O + 7 H2 --> 7 H2O + 14 H+ + 14 e- </span>
<span>Finally, add the two half reactions and simplify by cancelling anything that is on both sides. This will give you the final balanced reaction: </span>
<span>2 NO2 + 7 H2 --> 2 NH3 + 4 H2O </span>
<span>So, the answer to the original question is (A) 7
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