Metals: Properties, Structure, and Applications in Construction
Introduction to Metals
Metals are materials composed of metallic elements, characterized by atoms held together by metallic bonds. These bonds influence their properties, allowing ion layers to displace without rupture, determining plasticity. Metals are known for their electrical and thermal conductivity. In nature, metals are often combined with other elements. Metallurgy is the process of extracting metals by studying their properties. Iron extraction leads to steel.
Ferrous Metals
Ferrous metals,
Read MoreComplexation and Buffers in Chemistry
Complexation in Chemistry
Complexation is the process of forming a complex, which is a molecule or ion composed of multiple components, typically a central metal ion or molecule surrounded by one or more ligands. Complexation can be classified based on various criteria.
Types of Ligands
- Monodentate: One binding site (e.g., chloride, ammonia)
- Bidentate: Two binding sites (e.g., ethylenediamine, oxalate)
- Polydentate: Multiple binding sites (e.g., EDTA, citrate)
Coordination Number
- Mononuclear: One central
Atomic Structure, Bonding, and Chemical Principles
Atomic Structure and Properties
- Know the basic structure of an atom, in terms of sub-atomic particles (protons, neutrons and electrons), and discuss their basic properties and how they are arranged in the atom.
- Bohr theory of atomic structure.
- Four quantum numbers. (principle, angular momentum, magnetic and spin)
- Interpret the periodic table, and identify, describe and explain particular trends in the periodic table (ionisation energy, effective nuclear charge, atomic and ionic radii, electronegativity,
- Know the basic structure of an atom, in terms of sub-atomic particles (protons, neutrons and electrons), and discuss their basic properties and how they are arranged in the atom.
Solubility, Complexation, and Buffers in Pharmaceutical Science
Solubility Expression
Solubility is defined as the concentration of a solute in a solvent when the solution becomes saturated at a specific temperature and pressure. It is expressed as:
- Molarity (M): Moles of solute per liter of solution (mol/L).
- Molality (m): Moles of solute per kilogram of solvent (mol/kg).
- Parts per million (ppm): Milligrams of solute per liter of solution, often used for very low solubility levels.
- Percentage concentration: Expressed as weight/volume (% w/v) or weight/weight (% w/
History of the Periodic Table and Atomic Properties
How to Identify Elements
In 1830, John Jacob Berzelius, a Swedish chemist (1779-1848), proposed a method to represent the elements: using the first letter in Latin or, if two or more elements had the same initial, the initial letter followed by another present in the Latin name. For example, N for nitrogen, Na for sodium, and Ni for nickel.
Early Grouping of Elements
Many studies early this century established that the elements could be grouped into families with similar chemical properties, such as
Read MoreOptimizing Radiographic Processing: Techniques & Maintenance
Extended Processing in Mammography
- Extended Processing – Particularly useful in mammography
- 3 minutes (standard time is 90 seconds)
- Developer immersion time – doubled, but it is not necessary to alter developer temperature
- Significant disadvantage: longer dry-to-drop time.
- 2 principal advantages of EXTENDED PROCESSING: Greater image contrast & low patient dose
- Contrast increased by approximately 15%
- Image receptor sensitivity increased by at least 30%
- Thus, patient dose is reduced by at least 30%
- Improvements