Fundamental Concepts of Atomic Structure and Chemical Bonding
Subatomic Particles and Their Discoverers
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Electron: Discovered by J.J. Thomson in 1897.
- Mass: Approximately 1/1837 of a proton’s mass.
- Mass (kg): 9.1 x 10-31 kg.
- Charge: -1 (relative charge).
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Proton: Discovered by E. Rutherford in 1920.
- Mass (atomic mass unit, U): 1 U.
- Mass (kg): 1.7 x 10-27 kg.
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Neutron: Discovered by J. Chadwick in 1932.
- Mass (atomic mass unit, U): 1 U.
- Mass (kg): 1.7 x 10-27 kg.
- Charge: 0 (neutral).
Models of the Atom
Rutherford’s Planetary Model
The planetary model of the atom was proposed
Read MoreElectrostatics Fundamentals: Charge, Conductors, and Coulomb’s Law
Electrostatics: The Study of Static Electric Charges
Electrostatics is the study of electric charges at rest. Objects can be electrified through three primary methods:
- Friction
- Contact
- Induction
Electric Charges (Q) and Atomic Structure
- Protons and electrons possess electric charges (positive and negative, respectively).
- Forces of attraction between these particles form atoms.
- Every atom consists of a positively charged nucleus surrounded by negatively charged electrons.
- Electrons across all atoms are identical,
Essential English: Verbs, Questions, Time, Numbers & More
The Verb “To Be” (Ser/Estar)
The verb “to be” is fundamental in English, equivalent to “ser” or “estar” in Spanish/Catalan.
Conjugation: Affirmative and Negative Forms
| Affirmative | Negative | Contraction |
|---|---|---|
| I am | I am not | I’m not |
| You are | You are not | You aren’t |
| He/She/It is | He/She/It is not | He/She/It isn’t |
| We are | We are not | We aren’t |
| You are | You are not | You aren’t |
| They are | They are not | They aren’t |
Essential Questions for Introductions
Here are some common questions to ask when getting to know someone:
- What is your name? (Spanish:
Essential Concepts in Chemistry, Biology & Materials Science
Surface Tension Measurement Techniques
Surface tension, a critical property of liquids, can be accurately measured using several established methods:
Measurement Methods
- Du Noüy Ring Method: Measures the force required to pull a ring out of a liquid.
- Wilhelmy Plate Method: Measures the force exerted on a plate partially submerged in a liquid.
- Drop Weight Method: Measures the weight of drops falling from a capillary.
- Pendant Drop Method: Analyzes the shape of a pendant drop to determine surface tension.
Laboratory Equipment and Usage Protocols
Doping Fluorometric Assay Method
This method is used for detecting peptide hormones. Fluorescence spectroscopy is a type of electromagnetic spectroscopy that analyzes the fluorescence of a sample. The electrons of a molecule are excited by a beam of light of lower energy, which is detected by a fluorometer.
Hematological Analyzer and Cytometer
This equipment is used for hematological parameters and for detecting blood transfusion. Flow cytometry is a technique for counting, examining, and sorting microscopic
Read MoreKey Organic Chemistry Principles: Oil Hydrogenation, Amine Basicity, Huckel’s Rule
This document provides a detailed explanation of the hydrogenation of oil, preventive measures to minimize oil rancidity, the basicity of aromatic amines, and Huckel’s rule.
Oil Hydrogenation & Rancidity Prevention
Understanding Oil Hydrogenation
Hydrogenation is a chemical reaction involving the addition of hydrogen to unsaturated fatty acids in oils. This process converts liquid oils into semi-solid or solid fats, making them more stable and resistant to oxidation.
Types of Hydrogenation Processes
- Partial