Matter: Properties, States, Changes, and Atomic Theory
Matter: Properties, States, and Transformations
Matter is anything that occupies space and has mass. Matter exhibits both general and characteristic properties.
General and Characteristic Properties of Matter
- General properties are those whose values do not identify a specific substance.
- Characteristic properties are those that have a unique and characteristic value for each substance.
The magnitude of any feature of matter, or the changes it can undergo, can be measured; that is, it can be expressed
Read MoreAg-Pb Alloy System: Understanding Phase Diagrams
Ag-Pb Alloy System: Phase Diagram Explained
The lead-silver (Ag-Pb) system exemplifies a simple eutectic system. Silver and lead are miscible in all proportions and do not react chemically. When molten silver and lead are mixed together, a single homogeneous solution is formed. The system consists of the following phases:
- Solid silver (Ag)
- Solid lead (Pb)
- Solution of molten silver and lead
- Vapor
Since pressure has a negligible effect on equilibrium, the system can be represented by a temperature and concentration
Read MoreUnderstanding Chemical Bonds: Atomic Stability and Lewis Octet Rule
Chemical Bonds
Atomic Stability
3.1 Lewis Octet Rule
3.2 Ionic Bonds: Properties of Ionic Compounds
3.3 Covalent Bonds: Properties of Covalent Compounds. Intermolecular Forces
3.4 Metallic Bonds: Properties of Metallic Compounds
In nature, we observe a variety of simple and compound substances, consisting of combinations of atoms, either of the same or different elements. However, with the exception of noble gases, we rarely find substances consisting of individual atoms. This leads us to ask two questions:
Read MoreChemical Bonds: Ionic, Covalent, and Metallic
Understanding Chemical Bonds: Types and Properties
A chemical bond arises when atoms interact, leading to compounds with lower energy than the separated atoms. To achieve a noble gas configuration, atoms can gain, lose, or share electrons. Depending on how this is achieved, bonds can be ionic, covalent, or metallic. The properties of compounds depend on the type of bond between their atoms.
Ionic Bond
An ionic bond occurs between metallic and nonmetallic elements. Metals give up their extra electrons
Read MoreAtomic Structure: Electrically Charged Particles
Elective Nature of Matter
When two bodies with electric charges of the same sign approach, they repel each other.
When two bodies with electric charges of opposite signs approach, they attract each other.
Electroscope
An electroscope is a device used to detect charged bodies. There are two ways to detect if bodies are charged:
- Contact: If a charged rod touches the metal ball, the charge will reach the sheets. Since the sheets have the same charge, they repel.
- Induction: If a charged rod is brought near,
Fundamental Concepts in Physics and Chemistry
Physics
Physics: Part of the science of physical phenomena.
- Phenomenon: Any event under study.
- Physical phenomena: A process that does not alter the nature of the substances involved.
Chemistry
Chemistry: Part of the science of chemical phenomena.
- Chemical phenomena: A process that changes the nature of the substances involved.
The Scientific Method
Steps:
- Observation: Focusing on natural events to reproduce them in a laboratory setting.
- Experimentation: Repeating the phenomenon under study in the laboratory,