Understanding Physics and Chemistry: Basic Principles
Physics and Chemistry: Basic Concepts
Physics
Part of the science of physical phenomena.
- Phenomenon: Any event under study.
- Physical Phenomena: Processes that do not alter the nature of the substances involved.
Chemistry
Part of the science of chemical phenomena.
- Chemical Phenomena: Processes that change the nature of the substances involved.
The Scientific Method
The scientific method consists of the following steps:
- Observation: Noting fixed natural events in order to reproduce them in the laboratory.
Water Treatment, Chemical Changes, and Alloys
Topic 5: Water Treatment Methods
Drinking water is not obtained by simple decanting. Water obtained from rivers and lakes is often unfit for human consumption. It’s usually murky, and if left to stand, waste deposits at the bottom.
Decanting (using a decanting funnel): Muddy water is carefully poured into another container to separate and extract the sediments. After decanting, the water may remain murky due to small suspended particles. These particles can be separated by filtration using filter
Read MoreMatter, Mixtures, and Material Properties Explained
Basic Concepts of Matter
Atom: Basic parts which consist of matter (protons, neutrons).
Molecule: Clusters of atoms that are in some substances (H2O).
Chemical element: Pure substances found in nature consist of countless atoms (gold, copper).
Compound: Substance formed by two or more elements with a constant rate and specific (H2O, CO2).
Pure substance: Elements with novel composition or properties (sugar, iron).
Mixtures and Separation Techniques
Mixture: Substances formed by several elements or compounds
Read MoreChemistry 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
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