Final answer:
The correct answer is D. 20.18 g of Neon (Ne), as it represents 1 mole which contains the same number of atoms as 12.01 g of carbon, adhering to Avogadro's number.
Step-by-step explanation:
The question asks which among the provided options contains the same number of atoms as 12.01 g of carbon. Since we know that 12.01 g of carbon is equivalent to 1 mole of carbon-12 and contains Avogadro's number of atoms, which is approximately 6.022 x 1023 atoms, we can only find substances that weigh as much as their molar mass in grams to have an equal number of atoms.
For each substance provided, we compare the given mass to its molar mass:
- For Lithium (Li), with an atomic mass of about 7 g/mol, 13.88 g would correspond to nearly 2 moles, thus having more atoms than 12.01 g of carbon.
- For Helium (He), with an atomic mass of about 4 g/mol, 12.0 g equates to 3 moles, therefore, it also contains more atoms than 12.01 g of carbon.
- For Boron (B), with an atomic mass of about 10.81 g/mol, 5.4 g amounts to roughly 0.5 moles, consequently having fewer atoms than 12.01 g of carbon.
- For Neon (Ne), with an atomic mass of about 20.18 g/mol, 20.18 g represents exactly 1 mole, which contains the same number of atoms as 12.01 g of carbon.
Therefore, the correct answer is D. 20.18 g of Ne, as both 20.18 g of Ne and 12.01 g of carbon consist of 1 mole, and hence the same number of atoms.