| An atom consists of three main constituents: Protons and Neutrons (nucleons) located in the nucleus Electrons orbiting the nucleus in shells. | Constituents of an Atom |
| What are nucleons? | Protons and Neutrons, which are located in the nucleus of an atom, are called nucleons. |
| Here are the proton properties: | Proton Properties |
| What is the specific charge of a proton? | The specific charge of a proton is 9.58 x 10^7 Ckg^-1. |
| Here are the neutron properties: | Neutron Properties |
| What is the charge and specific charge of a neutron? | The charge of a neutron is 0 C, and the specific charge is 0 Ckg^-1 |
| Here are the electron properties: | Electron Properties |
| What is the specific charge of an electron? | The specific charge of an electron is 1.76 x 10^11 Ckg^-1 |
| The specific charge of a particle is the ratio of its charge to its mass, calculated as: | Specific Charge |
| How do you calculate the specific charge of a particle? | The specific charge is calculated by dividing the charge (Coulombs) by the mass (kilograms) of the particle. |
| The number of protons in an atom, denoted by Z. | Proton Number (Z) |
| What is the nucleon number (A) of an atom? | The nucleon number is the total number of protons and neutrons in an atom, denoted by A. |
| The notation for an element is written as: where X is the symbol for the element, Z is the proton number, and A is the nucleon number. | Element Notation |
| What do the letters Z and A represent in element notation? | Z represents the proton number and A represents the nucleon number. |
| Isotopes are atoms with the same number of protons but different numbers of neutrons. | Isotopes |
| What is carbon-14 and how is it used? | Carbon-14 is a radioactive isotope of carbon used for carbon dating to estimate the age of objects containing organic material. |
| Carbon dating involves calculating the percentage of carbon-14 remaining in an object and using its half-life to estimate the object's age. | Carbon Dating |
| How does carbon dating work? | It uses the starting value of carbon-14 (constant in living things) and its half-life to determine the age of an object by measuring the remaining carbon-14. |
| The strong nuclear force (SNF) keeps nuclei stable by counteracting the electrostatic force of repulsion between protons. | Strong Nuclear Force (SNF) |
| What does the strong nuclear force act on? | The strong nuclear force acts on nucleons (protons and neutrons) within the nucleus. |
| The strong nuclear force is attractive up to 3 femtometers (fm) but becomes repulsive below 0.5 fm. | Range of Strong Nuclear Force |
| What does the strong nuclear force counteract? | The strong nuclear force counteracts the electrostatic repulsion between protons in the nucleus. |
| Unstable nuclei have too many protons, neutrons, or both, making the strong nuclear force (SNF) insufficient to keep them stable, leading them to decay to achieve stability. | Unstable Nuclei |
| What causes unstable nuclei to decay? | They decay due to having too many protons, neutrons, or both, which results in an insufficient strong nuclear force (SNF) to maintain stability. |
| Alpha decay occurs in large nuclei with too many protons and neutrons. | Alpha Decay |
| What happens during alpha decay? | The proton number decreases by 2, the nucleon number decreases by 4. |
| Beta-minus decay occurs in nuclei that are neutron-rich (have too many neutrons). | Beta-Minus Decay |
| What happens during beta-minus decay? | The proton number increases by 1, the nucleon number stays the same. |
| What was the initial belief about particles emitted during beta-minus decay? | Scientists initially believed only an electron (beta-minus particle) was emitted from the nucleus during beta-minus decay. |
| Neutrinos were hypothesized to account for energy discrepancies observed during beta-minus decay, later confirmed through observation. | Neutrinos |
| Why were neutrinos hypothesized? | They were hypothesized to explain the non-conservation of energy observed in the energy levels of particles before and after beta-minus decay. |
| For every type of particle, there is an antiparticle that has the same rest energy and mass but all other properties are opposite. | Antiparticle |
| Give an example of a particle and its corresponding antiparticle. | The positron is the antiparticle of the electron. An electron antineutrino is the antiparticle of a neutrino. |
| Comparison of properties between particles and their antiparticles: | Properties Comparison |
| Electromagnetic radiation travels in packets called photons, which transfer energy and have no mass. | Photons |
| How is the energy of photons related to the frequency of electromagnetic radiation? | The energy of photons is directly proportional to the frequency of electromagnetic radiation, as shown in the equation: E = hf, where h is the Planck constant. |
| The Planck constant h is equal to approximately 6.63 × 10⁻³⁴ J s. | Planck Constant |
| The relationship between energy and wavelength can also be expressed as: E = hc/λ | Energy Wavelength Relationship |
| Annihilation is where a particle and its corresponding antiparticle collide, resulting in their masses being converted into energy. | Annihilation |
| What happens to the energy released during annihilation? | The energy, along with the kinetic energy of the two particles, is released in the form of 2 photons moving in opposite directions to conserve momentum. |
| An important application of annihilation is in a PET scanner, which allows for 3D images of the inside of the body, aiding in medical diagnoses. | Application of Annihilation |
| How does a PET scanner utilize annihilation? | A positron-emitting radioisotope is introduced into the patient. As positrons are released, they annihilate with electrons in the patient’s system, emitting gamma photons that can easily be detected. |
| Pair production is the process where a photon is converted into an equal amount of matter and antimatter. | Pair Production |
| Under what conditions can pair production occur? | Pair production can occur only when the photon has an energy greater than the total rest energy of both particles; any excess energy is converted into the kinetic energy of the particles. |
