Matter: Kinetic Theory, Properties, and Classifications

Kinetic Theory of Matter

• Matter is made up of particles.
• These particles are constantly moving because they have kinetic energy.
• There are spaces between the particles.
• There are attractive forces between particles, and these become stronger as the particles move closer.
• All particles have energy. The temperature of a substance is a measure of the average kinetic energy of the particles.
• A change in phase may occur when the energy of the particles is changed.

Boyle's Law

The pressure of a fixed quantity of gas is inversely proportional to the volume it occupies, as long as the temperature remains constant. P₁ × V₁ = P₂ × V₂

Gay-Lussac's and Charles's Law

The volume of an enclosed sample of gas is directly proportional to its absolute temperature, provided the pressure is kept constant. V₁ / T₁ = V₂ / T₂

Some Properties of Matter

• Strength: Materials can be strong and resist bending or weak and bend easily.
• Thermal Conductivity: Materials that conduct heat are thermal conductors.
• Electrical Conductivity: Materials that conduct electricity are electrical conductors.
• Malleability: Malleable materials can be easily formed into different shapes.
• Ductility: Ductile materials can be formed into long wires.
• Brittleness: Brittle materials break easily.
• Magnetism: Magnetic materials have a magnetic field.
• Density: Density is the mass per unit volume.
• Boiling and Melting Points: The boiling and melting points of substances tell us the temperature at which the substance will boil or melt. This helps us classify substances as solids, liquids, or gases at specific temperatures.

Matter

Matter: Anything that has both mass and volume.

Pure Substance

Matter with constant composition. All particles have the same properties.

Element

A substance made up of atoms with the same atomic number.

Compound

A substance made from two or more elements, chemically combined.

Mixture

Matter with variable composition. Made up of two or more substances.

Homogeneous

A mixture made up of particles that are uniformly distributed.

Heterogeneous

A mixture where particles are not uniformly distributed.

Representations

• Atoms are represented by single spheres. Spheres of the same size and color represent atoms of the same element.
• Molecules are represented by two or more spheres joined together.
• Molecules of Elements are represented by two or more spheres of the same size and color joined together.
• Molecules of Compounds are represented by two or more spheres of different sizes and colors joined together.