Understanding Matter: Substances, Mixtures, Solutions
Understanding Matter: Substances, Mixtures, and Solutions
True or False:
- T – A substance is matter that is always made up of the same combination of atoms.
- F – A mixture is matter that is made up of atoms of two or more elements chemically bonded together.
- F – In a homogeneous mixture, substances are not evenly mixed.
- T – In a mixture, the components keep their own properties.
Multiple Choice:
- In which way do mixtures differ from compounds?
- C. A mixture requires a physical change; a compound requires a
Chemistry Concepts Explained: Reactions, Polymers, and More
Rosenmund Reaction
In the presence of BaSO4, an aldehyde is obtained upon reduction of an acid chloride. This reaction is called the Rosenmund reaction. The product is an aldehyde, and the reagent is Pd/BaSO4.
Polypeptide Bond Formation
A peptide bond is formed from amino acids between one -COOH group and another -NH2 group by the removal of one molecule of water.
Increasing Order of Electron Affinity for Halogens
I2 < Br2 < F2 < Cl2
Usefulness of DNA Fingerprinting
Individual organisms are identified
Read MoreUnderstanding Atoms and Bonds
The Atom’s Composition
The atom consists of:
- Nucleus: Located at the center, it has a positive charge and contains almost all of the atom’s mass.
- Cortex (Electron Cloud): Contains electrons, which are negatively charged and orbit the nucleus, contributing to the atom’s small mass.
Atomic Masses
Atomic masses are very small, so units are used to make calculations.
Isotopes
Isotopes are atoms of the same element with the same atomic number but different mass numbers. Each isotope has a different mass-dependent
Read MoreMolecules to Metabolism: Carbon Compounds in Life
Molecules to Metabolism
Molecular Biology Explains Living Processes
Molecular biology explains living processes in terms of the chemical substances involved.
- It involves explaining biological processes from the structures of the molecules and how they interact with each other.
- Many molecules are important to living organisms, including water, carbohydrates, lipids, proteins, and nucleic acids.
- Proteins are one of the most varied macromolecules, performing many cellular functions, including catalyzing
Understanding Atoms, Molecules, and Cells: A Primer
Atom: The Basic Unit
An atom is the smallest unit of a chemical element that retains its identity and properties and cannot be divided by chemical processes.
Atomic Structure
- Proton: A subatomic particle with a positive (+) charge.
- Neutron: An uncharged subatomic particle.
- Electron: A subatomic particle with a negative (-) charge.
Chemical Elements and Bonds
A chemical element is a substance that cannot be decomposed by chemical reactions. Substances are formed by molecules of a single type, such as O,
Read MoreUnderstanding Electrostatics: Principles and Applications
Electrostatics
Early Observations
Thales observed that rubbing amber with cat fur attracted feathers. Gilbert manufactured the versorium.
Types of Electricity
Charles du Fay discovered that rubbing glass with silk electrified objects, and similar objects repelled each other. He deduced two types of electricity: resinous and vitreous.
In 1747, Franklin named the charge gained by rubbed bodies as positive and the charge lost as negative. Bodies with the same charge repel, while those with different charges
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