ISOTOPES, IONS, AND ATOMS WORKSHEET 2 Atomic # Mass # #p #e #n charge Symbol 1) 14 16 +4 2) 75 36 42 3) 51 54 79 4) 99 252 96 5) 208 82 Pb
6) 52 76 -2 7) 113 48 49 8) 42 98 +6 17 7 N
9) 10) 209 83 +5 110 11) 46 Pd
The Correct Answer and Explanation is:
Completed Table
| Atomic # | Mass # | #p | #e | #n | Charge | Symbol |
|---|---|---|---|---|---|---|
| 1) 14 | 16 | 14 | 10 | 2 | +4 | Si⁴⁺ |
| 2) 75 | 117 | 75 | 36 | 42 | +39 | Re³⁹⁺ |
| 3) 51 | 105 | 51 | 54 | 54 | -3 | Sb³⁻ |
| 4) 99 | 252 | 99 | 96 | 153 | +3 | Es³⁺ |
| 5) 82 | 208 | 82 | 82 | 126 | 0 | Pb |
| 6) 52 | 76 | 52 | 54 | 24 | -2 | Te²⁻ |
| 7) 48 | 113 | 48 | 49 | 65 | -1 | Cd⁻ |
| 8) 42 | 98 | 42 | 36 | 56 | +6 | Mo⁶⁺ |
| 9) 7 | 17 | 7 | 7 | 10 | 0 | N |
| 10) 83 | 209 | 83 | 78 | 126 | +5 | Bi⁵⁺ |
| 11) 46 | 106 | 46 | 46 | 60 | 0 | Pd |
Textbook-Style Explanation (300 Words)
Atoms are composed of three primary subatomic particles: protons (p), neutrons (n), and electrons (e). The atomic number is the number of protons and defines the identity of the element. For example, any atom with 6 protons is a carbon atom. The mass number is the sum of protons and neutrons, giving the total mass of the nucleus. To find the number of neutrons, subtract the atomic number from the mass number:
neutrons = mass number – atomic number
Atoms can become ions by gaining or losing electrons. If an atom loses electrons, it becomes a positively charged cation, and if it gains electrons, it becomes a negatively charged anion. The charge of an ion is determined by subtracting the number of electrons from the number of protons:
charge = protons – electrons
Isotopes are atoms of the same element (same number of protons) but with different numbers of neutrons, and therefore different mass numbers. For example, carbon-12 and carbon-14 are isotopes of carbon with 6 protons but different neutrons.
In the worksheet above, atoms and ions of various elements are analyzed based on their subatomic composition. For instance, in row 1, an atom with atomic number 14 (silicon) has 14 protons, and with a charge of +4, it must have 10 electrons. If its mass number is 16, then it has 2 neutrons. This is highly unusual but theoretically possible.
Understanding isotopes and ions is crucial in fields like chemistry, physics, medicine (radiotherapy), and environmental science (isotope tracing), where the stability, reactivity, and identity of elements play critical roles.
