To determine which isotopes have 8 neutrons in their nucleus, we need to follow these steps:
1. Understand the Composition of an Atom:
- An atom consists of protons, neutrons, and electrons.
- The atomic number of an element indicates the number of protons.
- The mass number of an isotope is the total number of protons and neutrons in its nucleus.
2. Identify the Atomic Numbers:
- Atomic number of Oxygen (O) = 8
- Atomic number of Carbon (C) = 6
3. Calculate the Number of Neutrons:
- For an isotope [tex]\( ^A \text{Element} \)[/tex], the mass number [tex]\( A \)[/tex] is given and the atomic number [tex]\( Z \)[/tex] is known.
- Number of neutrons = Mass number - Atomic number
Let's apply these steps to each isotope:
- O-15:
- Mass number (A) = 15
- Atomic number (Z) = 8
- Number of neutrons = 15 - 8 = 7
- O-17:
- Mass number (A) = 17
- Atomic number (Z) = 8
- Number of neutrons = 17 - 8 = 9
- C-13:
- Mass number (A) = 13
- Atomic number (Z) = 6
- Number of neutrons = 13 - 6 = 7
- C-14:
- Mass number (A) = 14
- Atomic number (Z) = 6
- Number of neutrons = 14 - 6 = 8
4. Identify Isotopes with 8 Neutrons:
- From the calculations:
- O-15 has 7 neutrons.
- O-17 has 9 neutrons.
- C-13 has 7 neutrons.
- C-14 has 8 neutrons.
Therefore, the isotope that has 8 neutrons in its nucleus is C-14.
