LESSON 1: STRUCTURE OF MATTER

What is matter composed of, according to the kinetic molecular model?

Matter is composed of discrete particles called molecules.

How do molecules behave according to the kinetic molecular model?

Molecules are in constant, random motion.

What is the motion of molecules called?

Thermal motion.

What happens to temperature as molecules move faster?

The faster the molecules move, the higher the temperature of the substance they form.

What exists between molecules?

Both attractive and repulsive forces, collectively known as intermolecular forces.

In the kinetic molecular model, what does the term "molecule" refer to?

Any particle that makes up matter: molecules, atoms, or ions.

What is Brownian motion?

The random, ceaseless motion of tiny particles suspended in a liquid or gas, caused by collisions with the surrounding molecules.

What are the forces between molecules called collectively?

Intermolecular forces (a combination of attractive and repulsive forces).

If the distance between molecules is very small (about molecular size), which force dominates?

Repulsive force is greater than attractive force.

If the distance between molecules is larger than molecular size, which force dominates?

Attractive force is greater than repulsive force.

If the distance between molecules is very large compared to molecular size, what happens to the intermolecular force?

The intermolecular force becomes negligible.

In a solid, how close are the molecules to each other?

Very close together.

How strong are the interaction forces between molecules in a solid?

Very strong.

What are molecules in a solid held at?

Fixed equilibrium positions, where each molecule can only oscillate (vibrate) around that position.

What volume and shape do solids have?

A definite volume and a definite shape.

What is a crystalline solid?

A solid with a crystal structure, where molecules are tightly bonded and arranged in a well-defined, periodic geometric pattern called a crystal lattice.

Give examples of crystalline solids.

Table salt, diamond, and most metals.

What is a crystal lattice?

A well-defined, periodic geometric arrangement of molecules that repeats in space, characteristic of crystalline solids.

What are the two types of crystalline solids?

Single-crystal (monocrystalline) solids and polycrystalline solids.

What is a polycrystalline solid?

A solid composed of many single-crystal grains bonded together in random orientations.

What is a single-crystal (monocrystalline) solid?

A solid in which the crystal lattice repeats in the same structure and orientation throughout the entire crystal.

Why can the same substance have very different physical properties?

Because it can have different crystal structures — for example, graphite and diamond, both made of carbon, have very different properties.

What is an amorphous solid?

A solid with no crystalline structure.

Give examples of amorphous solids.

Glass, asphalt, and rubber.

In a liquid, how do molecules compare to those in a solid in terms of distance?

Molecules in a liquid are farther apart than in a solid.

How do intermolecular forces in a liquid compare to those in a solid?

They are weaker than in a solid.

What happens to equilibrium positions of molecules in a liquid?

Molecules oscillate around equilibrium positions, but these positions can shift/change over time.

What volume and shape do liquids have?

A definite volume, but no fixed shape of their own — they take the shape of their container.

In a gas, how do molecules compare to those in a liquid in terms of distance?

Molecules in a gas are farther apart than in a liquid.

How large is the distance between gas molecules compared to their size?

Very large compared to the size of the molecules themselves.

How strong are the interaction forces between gas molecules?

Almost negligible, except during collisions.

How do gas molecules move?

Randomly and continuously in all directions (disordered motion).

What volume and shape do gases have?

No fixed volume or shape — they take the volume and shape of their container.

What is the plasma state?

A state of matter in which substances exist not as atoms or molecules, but as ions and free electrons.

Compare intermolecular distance: solid vs liquid vs gas.

Solid: very close together. Liquid: farther apart than solid. Gas: very large compared to molecular size.

Compare intermolecular bonding force: solid vs liquid vs gas.

Solid: very strong. Liquid: weaker than solid. Gas: very weak/negligible.

Compare molecular motion: solid vs liquid vs gas.

Solid: oscillates around a fixed equilibrium position. Liquid: oscillates around a shifting equilibrium position. Gas: random, disordered motion.

Compare compressibility: solid vs liquid vs gas.

Solid: incompressible. Liquid: incompressible. Gas: easily compressible.

Compare shape: solid vs liquid vs gas.

Solid: definite shape. Liquid: takes shape of container. Gas: takes shape of container.

Compare volume: solid vs liquid vs gas.

Solid: definite volume. Liquid: definite volume. Gas: depends on the container.

Kinetic molecular model (English)

Mô hình động học phân tử

Thermal motion (English)

Chuyển động nhiệt

Brownian motion (English)

Chuyển động Brown

Intermolecular force (English)

Lực liên kết phân tử

Equilibrium position (English)

Vị trí cân bằng

Crystal lattice (English)

Mạng tinh thể

Crystalline solid (English)

Chất rắn kết tinh

Amorphous solid (English)

Chất rắn vô định hình

Single crystal / Monocrystal (English)

Chất rắn đơn tinh thể

Polycrystalline solid (English)

Chất rắn đa tinh thể

Plasma state (English)

Thể Plasma