Understanding Coffee Brewing: Key Concepts and Techniques
1) Sensory Scoring Criteria
| Category | Focus | Sensory Indicators |
|---|---|---|
| Fragrance/Aroma | Smell before & after brewing | Floral, nutty, chocolatey, smoky; light roasts have brighter/fruitier notes, dark roasts are more smoky. |
| Flavor | Overall taste profile | Sweet, bitter, sour, complex |
| Aftertaste | Finish or lingering taste | Clean, smooth, or harsh |
| Acidity | Brightness, liveliness | Citrus, apple, wine-like |
| Body | Mouthfeel or texture | Light, medium, heavy |
| Balance | Harmony among traits | Well-rounded, even |
| Sweetness | Smoothness & pleasantness | Honey, |
Biology and Physics Concepts: Cell Structure to Forces
Characteristics of Living Organisms (MRS. GREN)
- Movement (change position)
- Respiration (convert nutrients) 呼吸
- Sensitivity (sense) 敏感
- Growth (permanent increase)
- Reproduction (gametes, fertilisation) 繁殖
- Excretion (waste products removed) 排泄
- Nutrition (taking of nutrients into the body)
Cell Structure
Animal Cells
- Cytoplasm: The jelly-like substance filling the cell.
- Cell Membrane: Controls substances entering and leaving the cell.
- Nucleus: Contains genetic material that controls how a cell grows
Ionic, Covalent, and Metallic Bonds: Properties and Formation
Ionic Bonds: Formation and Properties
An ionic bond is a chemical link formed between a metal and a non-metal. This typically involves elements from groups such as:
- Group IA: Alkali Metals
- Group IIA: Alkaline Earth Metals
- Group VIA: Chalcogens
- Group VIIA: Halogens
Characteristics of Ionic Compounds
- High Melting and Boiling Points: The ionic bond is very strong. A significant amount of energy is required to overcome the electrostatic forces of attraction between the ions in the crystal lattice.
- Hard but
Chemistry Core Concepts: Reactions, Calculations, and Analysis
Temperature Effects on Reaction Rate
As temperature increases, the rate of reaction increases. This is explained by collision theory:
- Particles gain more kinetic energy, causing them to move faster and collide more frequently.
- Crucially, a higher proportion of particles have energy equal to or greater than the activation energy.
- This leads to more successful collisions per second, increasing the rate of reaction.
Example: When hydrochloric acid reacts with magnesium, increasing the temperature causes
Read MoreEssential Concepts in Stereochemistry and Organic Reactions
Core Principles of Organic Chemistry
Fundamental Concepts in Stereochemistry
1. Defining Isomerism
Compounds with the same molecular formula but different structures, leading to distinct properties.
2. Understanding Optical Activity
The ability of a compound to rotate plane-polarized light, typically due to the presence of chiral centers.
3. Chiral and Achiral Molecules
- Chiral: Molecules that are non-superimposable on their mirror image.
- Achiral: Molecules that are superimposable on their mirror image.
4.
Read MoreEssential Definitions and Laws of Physical Chemistry
pure substance is a phase of uniform composition and invariant Q can not be broken by physical methods salt, alcohol .. Q elements pure substances can not separate x chemical methods: hydrogen, nitrogen compound.
. Pure substances made up of 2 or more elements and Q can be separated by chemical methods: marble, sucrose ..
mix is an aggregation of different substances Q occur without any reaction between them both can kimica separate x x physical methods. Ls atoms are called isotopes of the element