Answer:

Explanation:
Hello.
In this case, we can see that the mass of carbon of the unknown compound comes from the yielded mass of carbon dioxide, thus, we compute the moles of carbon as follows:

Moreover, the mass of hydrogen comes from the yielded water, therefore we can also compute the moles of water:

Then, to find the subscripts in the empirical formula, we divide by the moles of carbon as the smallest:

Whose molar mass is:

Thus, the ratio of the molecular formula to the empirical formula is:

Therefore, the molecular formula is twice the empirical formula:

Which is actually ethane.
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Mass number = number of protons + number of neutrons
mass number= 8 + 7= 15 ---> the answer is B.
You may feel cold when you touch certain kinds of matter because some matter gives off cold air. I’m NOT SURE
Explanation:
The teacher is most likely talking about the fractional distillation process.
Fractional distillation: It is a separation technique used to separate different components of the given mixture on the basis of their difference in boiling points of the different components. The component with lowest boiling point will get separate out first from the mixture and the vapors formed from boiling are condensed in a separate container.
So, when the fractional distillation of mixture of oils and fuels is carried out gasoline will separate out first due to lower boiling temperature and then kerosene followed by diesel and others (fuels and oils).
The independent variable is the one factor you manipulate or change in the experiment.
The dependent is what you are measuring. The independent is the one thing you are altering so you can carry out your experiment.