Chemistry Fundamentals: History, Matter, and States
History of Chemistry
The first experiences of humans as chemists involved the use of fire to transform matter. Obtaining iron from ore and glass from sand are clear examples. Gradually, humans realized that other substances also have this power of transformation. Great efforts were devoted to finding a substance that transforms a metal into gold, which led to the creation of alchemy. The accumulation of alchemical experiences played a vital role in the future establishment of chemistry. Chemistry
Maintaining Optimal Swimming Pool Water Quality
Why Not Use the Same Water Quality Criteria for Rivers, Beaches, and Swimming Pools?
- Natural marine environments have a higher capacity for purification and renewal than swimming pool facilities.
- Artificial purification is not possible in natural bodies of water.
- There is an increased likelihood of disease transmission and, therefore, a higher health risk in natural bathing environments compared to properly maintained pools.
What Does It Mean When We Say Water Is Physically Clean? Does It Mean the Water
Read MoreThomson, Rutherford, and Bohr Atomic Models
The Thomson Atomic Model
The Plum Pudding Model, also known as the raisin bread model, is a theory about atomic structure proposed in 1904 by Joseph John Thomson, discoverer of the electron. This was before the discovery of the proton and the neutron. In this model, the atom is composed of negatively charged electrons embedded in a positive “soup,” like raisins in a pudding. It was initially thought that electrons were distributed evenly throughout the atom. Later variations postulated a cloud of
Read MoreAtomic Models, Water Hardness, Lubricants, and Polymers
Bohr’s Atomic Model
Bohr’s atomic model, proposed by Niels Bohr in 1913, is a foundational concept in understanding atomic structure. According to this model, electrons orbit the nucleus of an atom in specific, quantized paths or energy levels. The key features of Bohr’s model are:
- Nucleus: The atom consists of a small, dense nucleus made up of protons and neutrons at its center.
- Energy Levels: Electrons move in fixed orbits around the nucleus, each corresponding to a specific energy level. These orbits
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,
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