<span>The answer to the question is the option C. it cannot be physically broken down into different types of atoms. This means that the material is an element, which is a pure substance. Because an element is a pure substance that is formed by one only type of atoms. For example, gold is an element and all its atoms are of the same type. That is also true for any of the 118 elements of the periodic table. Compounds (other kind of pure substances) can be broken down into molecules (which contain different kind of atoms, but always in the same proportion) and mixtures (non pure substances) have different kind of substances.</span>
Answer:
![\boxed {\boxed {\sf 0.255 \ mol \ C }}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%200.255%20%5C%20mol%20%5C%20C%20%7D%7D)
Explanation:
If we want to convert from grams to moles, the molar mass is used. This is the mass of 1 mole. They are found on the Periodic Table as the atomic masses, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
Look up the molar mass of carbon.
Set up a ratio using the molar mass.
![\frac {12.011 \ g \ C}{ 1 \ mol \ C}](https://tex.z-dn.net/?f=%5Cfrac%20%7B12.011%20%5C%20g%20%5C%20C%7D%7B%201%20%5C%20mol%20%5C%20C%7D)
Since we are converting 3.06 grams to moles, we multiply by that value.
![3.06 \ g \ C*\frac {12.011 \ g \ C}{ 1 \ mol \ C}](https://tex.z-dn.net/?f=3.06%20%5C%20g%20%5C%20C%2A%5Cfrac%20%7B12.011%20%5C%20g%20%5C%20C%7D%7B%201%20%5C%20mol%20%5C%20C%7D)
Flip the ratio. This way, the ratio is still equivalent, but the units of grams of carbon cancel.
![0.25476646 \ mol \ C](https://tex.z-dn.net/?f=0.25476646%20%5C%20mol%20%5C%20C)
The original measurement of grams (3.06) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.
The 7 in the ten-thousandth place tells us to round the 4 up to a 5.
![0.255 \ mol \ C](https://tex.z-dn.net/?f=0.255%20%5C%20mol%20%5C%20C)
3.06 grams of carbon is approximately <u>0.255 moles of carbon.</u>
Density = Mass / Volume
Mass = Density * Volume
Mass = 45 * 7 * 8 * 10
Mass = 25,200 grams