The student's error is that she is assuming that the number of atoms in a sample is directly proportional to the mass of the sample. Avogadro's number (6.022 x 10²³) represents the number of atoms or molecules in one mole of a substance. However, the number of atoms in a given mass of a substance depends on the molar mass (mass per mole) of the substance, not the Avogadro's number.
The correct way to determine the number of atoms in a sample is to use the formula:
number of atoms = mass of the sample / molar mass
In this case, the molar mass of the substance is 30 g/mol, so the number of atoms in 150 g of the substance is:
number of atoms = 150 g / 30 g/mol = 5 mol
The correct answer is 5 moles of atoms, which is not equal to 5 times Avogadro's number. Therefore, the student's answer is incorrect.The student's error is that she is assuming that the number of atoms in a sample is directly proportional to the mass of the sample. Avogadro's number (6.022 x 10²³) represents the number of atoms or molecules in one mole of a substance. However, the number of atoms in a given mass of a substance depends on the molar mass (mass per mole) of the substance, not the Avogadro's number.
The correct way to determine the number of atoms in a sample is to use the formula:
number of atoms = mass of the sample / molar mass
In this case, the molar mass of the substance is 30 g/mol, so the number of atoms in 150 g of the substance is:
number of atoms = 150 g / 30 g/mol = 5 mol
The correct answer is 5 moles of atoms, which is not equal to 5 times Avogadro's number. Therefore, the student's answer is incorrect.