Tipos de Enlaces Químicos y Geometría Molecular
Enlace Iónico
Se presenta cuando los átomos participantes tienen una diferencia de electronegatividad apreciable, igual o mayor a 1.7. Es una fuerza electrostática que se establece debido a que se forman iones.
Los compuestos iónicos se caracterizan por:
- Ser sólidos a temperatura ambiente.
- Presentar altos puntos de ebullición y fusión.
- Facilidad para romperse en estado sólido (fragilidad).
- Ser malos conductores del calor y la electricidad en estado sólido (pero buenos conductores fundidos o en
Chemical Ions, Compounds, Formulas, and Nomenclature
Ions, Compounds, and Chemical Formulas
Understanding Ions
An ion is a charged particle formed when a neutral atom or group of atoms gains or loses electrons.
Cations: Positively Charged Ions
A cation is a positively charged ion formed when a neutral atom loses electrons (e.g., Na⁺).
| Na atom | 11 protons | 11 electrons |
|---|---|---|
Na⁺ ion | 11 protons | 10 electrons |
Anions: Negatively Charged Ions
An anion is a negatively charged ion formed when a neutral atom gains electrons (e.g., Cl⁻).
| Cl atom | 17 protons | 17 electrons |
|---|---|---|
Cl⁻ |
Understanding Matter: States, Mixtures, and Synthetic Materials
Matter is formed by particles. A model represents how matter behaves and is based on two key ideas:
- Matter is formed by tiny particles.
- These particles that make up matter are in constant movement.
States of Matter
Solid
Particles are tightly bound and do not produce any movement; they only vibrate.
Liquid
Particles are less united and less ordered, allowing them to move.
Gas
Particles are together but can move freely.
Changes of State
If the temperature changes, a substance can transition from one state to
Read MoreChemical Elements, Periodic Table, and Bonding Principles
Natural and Artificial Elements
There are approximately 90 naturally occurring elements. Necessary equipment in physics laboratories has allowed for the creation of additional, artificial elements. Few elements are found in their free state in nature; they are mainly found combined with other elements, forming compounds.
Element Distribution
Elements in the Earth’s Crust and Core
The element iron is abundant but primarily found in the Earth’s core. The Earth’s crust is mainly composed of oxygen and
Read MoreConcise Chemistry: Atomic Mass, Radiation, Water & Polymers
Atomic Structure and Radiation
- The relative atomic mass, Ar, or atomic mass, is the mass of an atom measured by comparison with the carbon atom -12.
- Alpha Particles: consist of two protons and two neutrons, i.e., are nuclei of helium atoms. When a radioactive nucleus emits an alpha particle, it is transformed into another with mass number A-4 and atomic number Z-2.
- Beta particles: are very fast electrons. They result from the disintegration of neutrons into a proton and an electron. When emitted, the
States of Matter: Properties, Kinetic Theory, and Elements
States of Matter: Properties and Characteristics
Solids
Solids have a definite mass, shape, and volume. They are generally difficult to compress, and their density is close to that of liquids. Key properties include elasticity, fragility, and hardness.
Liquids
Liquids have a definite mass and volume but take the shape of their container. They are difficult to compress and expand when heated. Important properties include surface tension, capillarity, and viscosity.
Gases
Gases have a definite mass but
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