Can you determine the exact number of neutrons in an atom by looking only at the periodic table?

• A. Yes, because the periodic table lists both the atomic number and the number of neutrons for each element.
• B. Yes, because the atomic number directly tells you the number of neutrons.
• C. No, because all atoms of an element have the same number of neutrons.
• D. No, because the periodic table shows the atomic number but not the mass number, and isotopes have different numbers of neutrons.

Answer: (D)

Verified step by step guidance

1. Understand that the periodic table provides the atomic number (Z) for each element, which represents the number of protons in the nucleus of an atom.
2. Recognize that the number of neutrons (N) in an atom is related to the mass number (A) by the formula: \(N = A - Z\), where \(A\) is the total number of protons and neutrons.
3. Note that the periodic table does not list the mass number (A) for elements because elements can exist as isotopes, which have the same atomic number but different mass numbers due to varying numbers of neutrons.
4. Since isotopes have different numbers of neutrons, and the periodic table only shows the atomic number, you cannot determine the exact number of neutrons by looking only at the periodic table.
5. Therefore, the correct conclusion is that the periodic table does not provide enough information to determine the exact number of neutrons in an atom.