Understanding Isotopes, Radioactivity, and Nuclear Reactions
Isotopes, Radioactivity, and Nuclear Reactions
Isotopes: Are atoms with the same atomic number but different atomic mass.
Radioactivity: The ability of some unstable nuclei to emit particles and/or electromagnetic radiation spontaneously. All nuclei with an atomic number greater than 83 are radioactive.
Internal Radiation: Internal radiation comes from radioactive substances in food, water, and air, which, when ingested or inhaled, are absorbed in living tissue. The main radioactive isotopes contained
Read MoreSodium Cycle Cation Exchange: Water Softening Explained
Sodium Cycle Cation Exchange Process
In municipal water softening, the sodium cycle cation exchange process softens a portion of the water to zero hardness. This softened water is then mixed with raw water to achieve the desired composition. The process utilizes ion exchange resins (zeolites) supported by a bed of gravel and sand. The type and quantity of resin depend on the water’s hardness.
Water passes through the resin bed, where calcium and magnesium cations are retained by the resins. In exchange,
Read MoreUnderstanding Matter, Mass, Weight, and Energy Concepts
Understanding Matter, Mass, Weight, and Energy
All we can see and touch is matter. There are also material things we cannot see, like air.
We note that matter occupies a certain portion of space we call volume. In the case of air, this is not obvious, but the next experience will help us prove it.
Mass
Mass represents the coefficient of inertia of a body, i.e., the resistance the body opposes to changes in its state of motion or stillness.
Weight
Weight is the measure of the gravitational force acting
Read MoreKey Concepts in Chemistry: Atoms, Reactions, Acids
Periodic Trends
- Ionization Energy: Energy required to remove an electron.
- Atomic Radius: The total distance from an atom’s nucleus to the outermost orbital of an electron.
- Electron Affinity: Energy change associated with the addition of an electron.
- Electronegativity: Ability to attract an electron. Fluorine is the most electronegative element.
Electron Configuration
- Hund’s Rule: When there are different orbitals of the same energy, they first get occupied with a single electron.
- Pauli Exclusion Principle:
Atomic Structure and Quantum Theory Fundamentals
Z (Atomic Number) = Number of Protons = Number of Electrons.
A (Mass Number) = Protons + Neutrons.
Origins of Quantum Theory
Although the Rutherford model successfully explained the observed experimental evidence, it was inherently inconsistent. It was known that when an electric charge (q) moves with accelerated motion, it loses energy in the form of electromagnetic radiation. The electron in circular motion around the nucleus is subjected to centripetal acceleration; therefore, it must lose energy.
Read MoreChemical Reactions and Laws: Essential Concepts
Chemical Reactions and Fundamental Laws
Chemical Reaction: A process involving the combination of two or more initial substances, called reagents, resulting in new products. These products possess physical and chemical properties entirely distinct from the starting substances.
Key Laws Governing Chemical Reactions
Lavoisier’s Law (Law of Conservation of Mass): In any chemical reaction, the total mass of the reactants is equal to the total mass of the products. In essence, “In a chemical reaction,
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