Three States of Matter p. 32 – 35 Chapter 2 Section 1 Vocabulary: states of matter solid liquid surface tension viscosity gas plasma

Three States of Matter The states of matter are the physical forms in which a substance can exist. They are solid, liquid, and gas. There is a fourth state of matter, plasma, but it is rarely found on Earth. It is very high in energy and therefore, difficult to contain. It is found in the sun and in stars. Solid Liquid Gas Plasma

Particles of Matter Matter is made up of tiny particles of matter called atoms and molecules. Atoms and molecules are always in motion and are always bumping into each other. The particles interact with each other, and the way they interact with each other helps determine the state of matter.

Solids A solid is state of matter that has a definite shape and a definite volume. The particles of a substance in a solid state are very close together. the attraction between them is stronger than the attraction between the particles of the same substance in the liquid or gaseous state. The particles of a solid move ever so slightly to vibrate in place. Each particle is locked in place by the particle around it. Solids Solid

There Are Two Kinds of Solids There are two kinds of solids – crystalline and amorphous. Crystalline solids have a very orderly, three- dimensional arrangement of particles. The particles are in a repeating pattern of rows. Examples include iron, diamond and ice. Amorphous solids are made of particles that do not have a special arrangement. Each particle is in one place, but the particles are not arranged in a pattern. Examples of amorphous solids are glass, rubber, and wax.

Liquids Liquid is the state of matter that has a definite volume, but no definite shape. It takes on the shape of its container. The particles of a liquid move fast enough to overcome some of the attractions between. The particles slide past each other until the liquid takes the shape of its container. Although liquids easily change shape, they do not easily change volume!

Liquids Have Unique Characteristics A special property of liquids is surface tension. Surface tension is a force that acts on the particles at the surface of a liquid. Surface tension causes some liquids to form round drops. Different liquids have different surface tensions. Because gasoline has a low surface tension, it forms flat drops. Water has high surface tension and forms round drops. Another important property of liquids is viscosity. Viscosity is the liquid’s resistance to flow. Substances like honey pour more slowly than water, so we say that honey has a high viscosity - the slower the substance flows, the higher the viscosity!

Gases Gas is the state of matter that has no definite shape and no definite volume. The particles of a gas move quickly. They can break away completely from one another. There is less attraction between particles of gas than between particles of the same substance in the solid or liquid state. The amount of space between gas particles can change. The gas particles will spread out as far as their container will let them. If they are in a small container, they may be closer together than they would be in large container.

The Matter Song – Solid or a Liquid or a Gas

Quiz Time! 1. How are the particles in a crystalline solid arranged? in a repeating pattern of rows that forms an orderly, three- dimensional figure. 2. How are the particles of an amorphous solid arranged? There is no special arrangement. Each particle is in one place, but they are not in any kind of pattern. 3. What is surface tension? It is a force that acts on the particles at the surface of a liquid. 4. What is viscosity? It is a liquid’s ability to flow. the thicker the liquid (honey), the higher its viscosity. The thinner the liquid (gasoline), the lower its viscosity.

5. The particles of a ______ are very far apart and move independently of each other. gas 6. The shape and volume of matter in the ______ state do not change. solid 7. One property that all particles of matter of matter have in common is they: A. never move in solids B. move only in gases C. move constantly D. None of the above C