Ionic Compounds Overview

Ionic Compounds

• Ionic compounds form when atoms gain or lose electrons to achieve a full valence shell.
• Atoms with similar valence electrons react to form a stable compound.
• Metals lose electrons (oxidation) and become cations (positive charge).
• Nonmetals gain electrons (reduction) and become anions (negative charge).
• Opposite charges attract (cation and anion) creating electrostatic attraction, forming an ionic bond.
• The number of charges on the cation and anion are represented as subscripts in the formula.
• Polyatomic ions are ions of more than one atom.
• Ionic compounds form crystalline lattice structures.
• Ionic compounds are hard, brittle, and do not conduct electricity in their solid state.
• They conduct electricity in their molten state and in aqueous solutions.
• The size and number of ions determine the lattice structure.
• The number of cations and anions must be equal to maintain neutrality.
• The structure of ionic compounds makes them high melting and boiling points.
• Ionic compounds dissolve in water, forming electrolytes.
• The process of dissolving ionic compounds in water is called dissociation.
• Most ionic compounds dissolve in water, but some have stronger bonds and are insoluble such as mercury iodide.
• Pyrolysis is heating substances to extreme temperatures in the absence of oxygen.
• Calcination is heating substances just below their melting point to remove impurities.

Synthesis and Decomposition Reactions

• Synthesis reactions are anabolic reactions where two reactants combine to form a product.
• Decomposition reactions are catabolic reactions where chemical bonds are broken to produce products.
• Single replacement reactions involve one element replacing another in a chemical compound.
• Double replacement reactions involve two compounds exchanging ions or groups of atoms.

The Nervous System

• Receptors detect stimuli and send signals to sensory neurons.
• Sensory neurons relay signals to interneurons in the spinal cord.
• Motor neurons carry signals from the interneurons to effectors (muscles or glands) to produce a response.
• The peripheral nervous system (PNS) includes all nerves outside the brain and spinal cord.
• The somatic nervous system is responsible for voluntary movements.
• The autonomic nervous system controls involuntary functions and body regulations.
• The sympathetic nervous system controls the "fight or flight" response.
• The parasympathetic nervous system controls the "rest and digest" response.

Earth's Magnetic Field

• The movement of liquid iron in Earth's outer core generates a magnetic field.
• The magnetic field lines point from the North Pole to the South Pole.
• Stronger magnetic fields have closer field lines.
• Two magnets attract each other when their field lines are aligned and repel each other when they are opposite.

Declination

• Declination is the angle at which Earth's magnetic field deviates from geographic north.
• Declination should be subtracted from your compass reading to find true north.

Explore the fascinating world of ionic compounds, focusing on their formation, properties, and unique structures. Learn how atoms achieve stability through oxidation and reduction, leading to the creation of cations and anions. Delve into how these compounds exhibit distinct characteristics like high melting points and electrical conductivity in various states.