model 2 - natural abundance information for magnesium\nisotope natural abundance on earth (%) atomic mass…

model 2 - natural abundance information for magnesium\nisotope natural abundance on earth (%) atomic mass (amu)\n²⁴mg 78.99 23.9850\n²⁵mg 10.00 24.9858\n²⁶mg 11.01 25.9826\n7 consider the natural abundance information given in model 2\n a. calculate the expected number of atoms of each isotope that will be found in a sample of 20 atoms of mg. hint: the number of atoms must be a whole number.\n b. is model 1 accurate in its representation of magnesium at the atomic level? explain.\n8. if you could pick up a single atom of magnesium and put it on a balance, the mass of that atom would most likely be ______ amu. explain your reasoning.\n9. refer to a periodic table and find the box for magnesium.\n a. write down the decimal number shown in that box.\n b. does the decimal number shown on the periodic table for magnesium match any of the atomic masses listed in model 2?\n10. the periodic table does not show the atomic mass of every isotope for an element.\n a. explain why this would be an impractical goal for the periodic table.\n b. is it important to the average scientist to have information about a particular isotope of an element? explain.\n11. what would be a practical way of showing the mass of magnesium atoms on the periodic table given that most elements occur as a mixture of isotopes?\n12. propose a possible way to calculate the average atomic mass of 100 magnesium atoms. your answer may include a mathematical equation, but it is not required.

model 2 - natural abundance information for magnesium\nisotope natural abundance on earth (%) atomic mass (amu)\n²⁴mg 78.99 23.9850\n²⁵mg 10.00 24.9858\n²⁶mg 11.01 25.9826\n7 consider the natural abundance information given in model 2\n a. calculate the expected number of atoms of each isotope that will be found in a sample of 20 atoms of mg. hint: the number of atoms must be a whole number.\n b. is model 1 accurate in its representation of magnesium at the atomic level? explain.\n8. if you could pick up a single atom of magnesium and put it on a balance, the mass of that atom would most likely be ______ amu. explain your reasoning.\n9. refer to a periodic table and find the box for magnesium.\n a. write down the decimal number shown in that box.\n b. does the decimal number shown on the periodic table for magnesium match any of the atomic masses listed in model 2?\n10. the periodic table does not show the atomic mass of every isotope for an element.\n a. explain why this would be an impractical goal for the periodic table.\n b. is it important to the average scientist to have information about a particular isotope of an element? explain.\n11. what would be a practical way of showing the mass of magnesium atoms on the periodic table given that most elements occur as a mixture of isotopes?\n12. propose a possible way to calculate the average atomic mass of 100 magnesium atoms. your answer may include a mathematical equation, but it is not required.

Answer

Explanation:

Step1: Calculate number of $^{24}$Mg atoms

Multiply total atoms by abundance. $20\times0.7899 = 15.798\approx16$

Step2: Calculate number of $^{25}$Mg atoms

$20\times0.1000 = 2$

Step3: Calculate number of $^{26}$Mg atoms

$20\times0.1101=2.202\approx2$

Answer:

$^{24}$Mg: 16 atoms, $^{25}$Mg: 2 atoms, $^{26}$Mg: 2 atoms

Explanation:

Model 1's accuracy depends on its representation details. If it doesn't match natural - abundance ratios and atomic - mass values, it's inaccurate. Without seeing Model 1, we can't give a definite answer. But in general, if it doesn't reflect the 78.99% abundance of $^{24}$Mg, 10.00% of $^{25}$Mg and 11.01% of $^{26}$Mg, it's inaccurate.

Answer:

We can't determine without seeing Model 1. If it doesn't match natural - abundance and atomic - mass data, it's inaccurate.

Explanation:

The most abundant isotope is $^{24}$Mg with 78.99% abundance. So the mass of a single randomly - picked atom is most likely to be the mass of $^{24}$Mg, which is 23.9850 amu.

Answer:

23.9850 amu because $^{24}$Mg is the most abundant isotope.

Explanation:

a. On the periodic table, the decimal number for magnesium is its average atomic mass, which is approximately 24.3050. b. None of the atomic masses in Model 2 exactly match the average atomic mass on the periodic table. The periodic - table value is a weighted average of the isotopic masses.

Answer:

a. 24.3050 b. No, the periodic - table value is a weighted average of isotopic masses.

Explanation:

a. There are many isotopes for some elements. Listing all their atomic masses would make the periodic table overly complex and cluttered. Also, the average atomic mass is more useful for general chemical calculations. b. For some specialized research (e.g., nuclear chemistry, mass - spectrometry), information about specific isotopes is crucial. But for general chemistry work like stoichiometry, the average atomic mass is sufficient. So it depends on the scientist's area of study.

Answer:

a. It would make the table complex and the average atomic mass is more useful. b. It depends on the scientist's area of study. For some specialized research, it's important; for general work, the average atomic mass suffices.

Explanation:

Show the average atomic mass. The average atomic mass takes into account the natural abundances of all the isotopes and gives a representative value for the element as it occurs in nature.

Answer:

Show the average atomic mass which is a weighted average of isotopic masses.

Explanation:

Multiply the mass of each isotope by its abundance in the sample of 100 atoms, sum these products. For example, if $n_1,n_2,n_3$ are the number of $^{24}$Mg, $^{25}$Mg and $^{26}$Mg atoms in 100 atoms, then average mass $=\frac{n_1\times23.9850 + n_2\times24.9858 + n_3\times25.9826}{100}$

Answer:

Multiply each isotopic mass by its number in 100 - atom sample, sum products and divide by 100.