Properties of solids, liquids and gases

Take a handout on the table (Foldable) Opening Assignment – Page 72 in your textbook Find the definitions of the two types of solids and add them to your foldable

Types of Solids Properties of a liquid Properties of a gas

Crystalline solid – define it. How are its particles arranged? Examples: Draw a picture (Mrs. Spock will provide picture) Gases are easily compressed (by adding pressure) What does that mean? Look at page 86. Amorphous solids - define it. How are the particles arranged? Draw figure 17 page 86

Types of Solids Crystalline Solids In many solids, particles form regular repeating patterns. These patterns create crystals. When a crystalline is heated it melts at a specific temperature called its melting point.

Types of solids Amorphous solids The particles are not arranged in a regular pattern Plastics, rubber and glass are amorphous solids. Do not melt at a specific temperature… no melting point. Become softer and softer.

Butter – amorphous solid

Gases - look at page 86 Properties of a gas Unlike a solid or a liquid, a gas can change volume easily Gasses are easy to compress!

What’s the difference between vapor and gas Vapor vs. Gas The word vapor is used to describe gases that are usually found as liquids. Good examples are water or mercury (Hg). Compounds like carbon dioxide are usually gases at room temperature so scientists will rarely talk about carbon dioxide vapor.

Look at page 73 in textbook Fill in the missing information on your foldable

Figure 5-A liquid takes the shape of it’s container but its _______________ Viscosity – define it Liquids are fluid.. What does that mean? Finish these sentence s– Liquids with high viscosity ____________________ Liquids with low viscosity _________________ Surface tension – define it. What can the insect do in Figure 7b page 74 because of surface tension?

Liquids Equivalent volumes Fluid A liquid can take the shape of its container but its volume does not change. Liquids is a fluid (just like gasses) because they can flow.

Properties of liquids Viscosity A liquid’s resistance to flowing. Depends on the sizwe and shape of the particles and the attraction between them, Some liquids flow slowly -- honey

Properties of liquids Surface tension The surface of liquids act like a skin. It is the result of an inward pull among water molecules that bring molecules on the surface together.

Water strider – walk on water

Water the polar molecule Water molecules are attracted to other water molecules. The oxygen end of water has a negative charge and the hydrogen has a positive charge. The hydrogens of one water molecule are attracted to the oxygen from the other water molecules. This attractive force is what gives water its cohesive properties

Float a paper clip on the surface of water

Paper clip lab How many paper clips can you fit into the glass before the water runs over……

Cohesion Water molecules are attracted to other water molecules. The oxygen end of water has a negative charge and the hydrogen has a positive charge. The hydrogens of one water molecule are attracted to the oxygen from the other water molecules. This attractive force is what gives water its cohesive properties .

Surface tension Surface tension is the name we give to cohesion of water molecules at the surface of a body of water. The cohesion of water molecules forms a surface “film” or “skin”. Some substances may reduce the cohesive force of water, which will reduce the strength of the surface “skin” of water.

Take a guess!!!! How many paper clips can you fit into the glass before the water runs over……