Key Concepts
* Mole: A mole is a unit of measurement for the amount of a substance. It represents 6.022 x 10^23 particles (atoms, molecules, etc.).
* Atomic Number: The atomic number of an element defines the number of protons in its nucleus.
* Mass Number: The mass number represents the total number of protons and neutrons in the nucleus of an atom.
* Isotopes: Isotopes of the same element have the same number of protons but different numbers of neutrons.
Comparison
| Feature | Ag-108 (Silver-108) | Pt-195 (Platinum-195) |
|-----------------------|----------------------|----------------------|
| Number of Atoms | 6.022 x 10^23 | 6.022 x 10^23 |
| Number of Protons | 47 | 78 |
| Number of Electrons| 47 | 78 |
| Number of Neutrons | 61 | 117 |
Explanation
* Atoms: Both a mole of Ag-108 and a mole of Pt-195 contain the same number of atoms (Avogadro's number: 6.022 x 10^23).
* Protons: The number of protons determines the element. Ag-108 has 47 protons (making it silver), while Pt-195 has 78 protons (making it platinum).
* Electrons: In a neutral atom, the number of electrons is equal to the number of protons.
* Neutrons: The difference in mass number (108 for Ag-108 and 195 for Pt-195) reflects the difference in their neutron count. You find the number of neutrons by subtracting the atomic number (protons) from the mass number.
Important Note: This comparison assumes that the atoms are in their neutral state (not ions). If the atoms are ions, the number of electrons will change.
