Materials: Properties, Types, and Applications
Matter
Paricular elementary (protons, neutrons, electrons) Source
Of materials.
**Natural materials** are obtained directly from nature (from living or inert). Ex: wood, granite, leather, cotton , wool …** Artificial materials** obtained from raw materials (materials extracted from the natural) after a process of recycled materials. are obtained from objects of same material.
Material Properties
A) MECHANICAL:
- Density: d = m / V.
- Hardness: hard material is + another when q is able to scratch the second.
Chemistry Notes: Hydrocarbons, Organic Chemistry, Thermodynamics, and More
Hydrocarbons
Reactions and Concepts
Wurtz Reaction
Alkyl halides react with metallic sodium in dry ether to form alkanes.
Sodium Acetate to Methane and Ethane
Sodium acetate heated with soda lime undergoes decarboxylation to form methane. It undergoes Kolbe’s electrolysis to yield ethane.
Conformations
Different spatial arrangements of atoms due to free rotation around a C-C single bond. Ethane exhibits eclipsed and staggered conformations, with staggered being more stable due to minimized repulsion.
Read MoreDiborane: Properties, Reactions, and Structure
Diborane is a chemical compound that consists of boron and hydrogen atoms, and has a molecular formula B²H⁶. This substance is highly unstable at room temperature. The compounds consisting of boron and hydrogen atoms are called boranes. Diborane is one of the simplest borane hydrides.
Methods of Preparation:
- When boron trifluoride is treated with Li or sodium hydride in ethereal solution, B2H6 is formed. 2BF3 + 6LiH – ether – 6LiF + B2H6. 2BF3 + 6NaOH – ether – 6NaOH + B2H6.
- B2H6 is obtained from
Properties of Copper Alloys, Nickel, Magnesium, Aluminum, and Annealing
Copper Alloys
Copper alloys: Great ductility without allowing thanks to that can be easily cold worked and matching not so easy. Corrosion resistance is outstanding in most normal environment. Mechanical properties are quite limited and they can improved with alloying materials. Most copper alloys cannot be hardened or strengthened by heat-treating procedures, cold working or solid solution to improve mechanical properties. Brass: copper + zinc. Alpha phase stable up to 35%. FCC crystal structure
Read MoreEvolution and Adaptation in Science
History of Science
As an example of the changes in ideas of this time, we will examine the behavior of a simple pendulum. Until the 16th century, Aristotle’s theory of pendulums held that the period (the length of time for one swing back and forth), depended on the amplitude (the distance the pendulum swung). We shall now test this idea, just as Galileo did.
A pendulum is a weight hanging from a fixed point by a string or wire which, when pulled back and released, is free to swing in and down due
Read MoreChemical Reaction Rates and Molar Concepts
Reaction Rate
Of a chemical reaction is defined in terms of the time it takes to make a reactant disappear or for a product to appear.
Collinson Theory
Chemical reactions break and form bonds as a result of collision between elemental units of the reactants. Not all cause the breaking or forming of bonds, not all collision are effective. Only collision with sufficient energy and whose molecules have the right orientation may break or form bonds.
Factors That Affect Reaction Rates
- Temperature: In reactions