how does the number given just below the symbol for magnesium (rounded to 0.01) compare with average mass (amu) of one magnesium atom
The mass given in the table is for 6.022E23 atoms of Mg.
To determine how the number below the symbol for magnesium compares with the average mass of one magnesium atom, we need to understand a few concepts.
The number below the symbol for an element represents its atomic number. In the case of magnesium, the atomic number is 12.
The average mass of one magnesium atom, on the other hand, is given by its atomic mass, which can be found on the periodic table. The atomic mass of magnesium is approximately 24.31 amu.
So, if we compare the number 12 (atomic number) with the average mass of one magnesium atom (24.31 amu), we can see that the atomic number is not directly related to the atomic mass.
The atomic number represents the number of protons in the nucleus of an atom, while the atomic mass represents the average mass of all the isotopes of that element, considering both protons and neutrons.
Therefore, the number 12 below the symbol for magnesium does not provide direct information about its average mass.
To compare the number given just below the symbol for magnesium with the average mass of one magnesium atom (in amu), we need to understand how atomic masses are determined.
The atomic mass of an element is the weighted average of the masses of all its isotopes. Isotopes are variations of an element that have the same number of protons but a different number of neutrons in their atomic nuclei. These variations can lead to different atomic masses for the same element.
The number given just below the symbol for magnesium in the periodic table is the atomic mass or atomic weight of magnesium. It is usually a decimal number that represents the average atomic mass of all the naturally occurring isotopes of magnesium.
To compare this atomic mass with the average mass of one magnesium atom (in amu), we can use the Avogadro's constant and the molar mass of magnesium. Avogadro's constant is approximately 6.022 × 10^23, which represents the number of atoms in one mole of any substance.
First, we need to find the molar mass of magnesium. The molar mass is the mass of one mole of a substance and is expressed in grams. The molar mass of magnesium is approximately 24.31 grams per mole.
Next, we can use Avogadro's constant to calculate the average mass of one magnesium atom. We divide the molar mass of magnesium by Avogadro's constant:
Average Mass of One Magnesium Atom (in amu) = Molar Mass of Magnesium / Avogadro's Constant
Therefore, to compare the number given just below the symbol for magnesium with the average mass of one magnesium atom (in amu), you would need to divide the atomic mass of magnesium (given in the periodic table) by the molar mass of magnesium and then divide the result by Avogadro's constant.