States of Matter

Solids A solid is a state of matter that has a definite shape and definite volume. –The particles of a solid are packed closely together and tightly fixed in one position. –Particles of a solid vibrate in place. Remember, all matter is made of moving particles.

Two Types of Solids Crystalline solids: solids whose particles form a regular repeating pattern (crystal). When they are heated, they melt at a specific temperature. –Ex: salt (melting point: 801° C) –sugar (melting point: 367° C)

Amorphous Solids ∙Amorphous Solids: solids whose particles are not arranged in a regular repeating pattern. ∙They do not have specific melting points. They become softer and softer as they are heated. ∙Ex: butter, chocolate, glass, rubber

“Firestorm” - Fire and States of Matter 1. What state or states of matter (solid, liquid, gas, plasma) are present in any fire? Which parts of the fire are which states of matter? (For example, what state(s) of matter is the flame? What state of matter is the CO 2 released by burning?) solid: trees/branches/plants ashes gas: CO 2 released by combustion H 2 O released by combustion liquid: water (sap) inside trees flame retardant used to extinguish fires plasma: flames lightning (can start wildfires)

“Firestorm” continued 2. According to the article, what devices or technologies have been engineered to help fight wildfires? How do these technologies work? infrared radar to detect where fires are burning “futuristic” firefighting suit prototype fire rating warning system planes designed to drop flame retardant on wildfires 3. What three "ingredients" are necessary for any fire to burn? fuel heat oxygen

Comparing the States

Liquids Liquid: a state of matter that has a definite volume and indefinite shape. The particles of a liquid are free to move around each other. They take the shape of the container they are in. Liquids are similar to solids in that they both have definite volumes.

Properties of Liquids: STEM Lab #3 1. Surface Tension: an increased “pull” among the top surface molecules of a liquid that brings these molecules closer together. Water molecules have a strong attraction to each other. This is called cohesion. Why such a strong attraction? –hydrogen bonding: positive H atoms in one water molecule are pulled toward the negative O atom in another water molecule. This strong pull reduces the total area of water’s surface, giving water’s surface a curved shape.

Another View of Surface Tension

Viscosity 2. Viscosity: a liquid’s resistance to flow. Viscosity depends on the size and shape of the molecules in a liquid and the attraction between them, not density. HIGH Viscosity: Flows slowly –Examples: honey, corn syrup LOW Viscosity: Flows quickly – Examples: vinegar, soda “Viscosity Race” results from STEM Lab #3: fastest 1. water 2. alcohol 3. oil 4. glycerin 5. pancake syrup 6. karo syrup slowest

Tie-Dye Milk Explanation What causes the food coloring to suddenly shoot out from the center? Milk is mostly water, but it also has undissolved vitamins, proteins, and fats held in solution Soap weakens the chemical bonds that hold together the proteins and fats, allowing the food coloring to mix with the milk. Soap molecules have two ends: 1. hydrophilic (water-loving) which dissolves in water 2. hydrophobic (water-fearing) which attaches to the fat in milk

High or low viscosity?

Gas Gas: a state of matter that has an indefinite shape and indefinite volume. Gas particles are constantly moving in all directions, colliding with each other and with the walls of the container. They fill up all available space. Gases are similar to liquids in that they both are considered fluids, a substance that flows. Unlike a liquid, its volume can change easily.

Plasma Plasma: a fourth state of matter that occurs when high-energy particles in a gas lose or gain electrons. Many forms of plasma give off visible light, including flames, lightning, and fluorescent light bulbs.

States of Matter and Energy Describe the relationship between states of matter and the energy and speedof their particles: Solid Liquid Gas Plasma Energy and Particle Speed INCREASE as you go up in state from solid → liquid → gas → plasma