Question

subatomic particles ii
objectives: use the atomic number and mass number to calculate the number of protons,
neutrons, and electrons.
a. complete the table

b. for each of the following isotopes, fill in the missing information. assume all
atoms are neutral

Explanation:

Step1: Recall atomic structure relationships

For a neutral atom:

• Atomic number \(Z=\) number of protons \(=\) number of electrons.
• Mass number \(A=\) number of protons \(+\) number of neutrons. So, number of neutrons \(=A - Z\).

Step2: Analyze \(^{23}\text{Na}\)

• Atomic number \(Z = 11\) (given).
• Mass number \(A=23\) (given).
• Number of protons \(=Z = 11\).
• Number of electrons \(=Z = 11\) (neutral atom).
• Number of neutrons \(=A - Z=23 - 11 = 12\).

Step3: Analyze \(K\)

• Atomic number \(Z = 19\) (given).
• Mass number \(A = 40\) (given).
• Number of protons \(=Z = 19\).
• Number of electrons \(=Z = 19\) (neutral atom).
• Number of neutrons \(=A - Z=40 - 19 = 21\).

Step4: Analyze \(Sr\)

• Atomic number \(Z = 38\) (given).
• Mass number \(A = 90\) (given).
• Number of protons \(=Z = 38\).
• Number of electrons \(=Z = 38\) (neutral atom).
• Number of neutrons \(=A - Z=90 - 38 = 52\).

Step5: Analyze \(F\)

• Atomic number \(Z = 9\) (given).
• Mass number \(A = 19\) (given).
• Number of protons \(=Z = 9\).
• Number of electrons \(=Z = 9\) (neutral atom).
• Number of neutrons \(=A - Z=19 - 9 = 10\).

Step6: Analyze Carbon isotopes

• For all carbon isotopes (Carbon - 12, Carbon - 13, Carbon - 14):
• Atomic number of carbon \(Z = 6\). So, number of protons \(=6\) and number of electrons \(=6\) (neutral atoms).
• For Carbon - 12: Mass number \(A = 12\), number of neutrons \(=A - Z=12 - 6 = 6\).
• For Carbon - 13: Mass number \(A = 13\), number of neutrons \(=A - Z=13 - 6 = 7\).
• For Carbon - 14: Mass number \(A = 14\), number of neutrons \(=A - Z=14 - 6 = 8\).

Answer:

The table in part A is correctly filled as shown in the problem statement (with calculations verified). For part B, the number of protons for all carbon isotopes is \(6\), number of electrons is \(6\) (since they are neutral), and number of neutrons for Carbon - 12 is \(6\), for Carbon - 13 is \(7\), and for Carbon - 14 is \(8\) (also as shown in the problem statement).