3 Main states of matter Solid Liquid Gas Scientists recognize a fourth state of matter called plasma, but it does not occur naturally on Earth except in the form of lightning bolts.
Solid A solid -definite shape and volume. Wood, iron, paper, and sugar are examples of solids
The particles in a solid are very tightly packed; when heated, a solid expands, but only slightly. Do you think a solid would conform to the shape of its container? Not Likely
Liquid A liquid is a form of matter that flows, has constant volume, and takes the shape of its container water, blood, and mercury The particles in a liquid are not rigidly held in place and are less closely packed than are the particles in a solid: liquid particles are able to move past each other.
Liquid A liquid -flows, has constant volume, and takes the shape of its container water, blood, and mercury The particles are not rigidly held in place and are less closely packed than the particles in a solid liquid particles are able to move past each other.
Does a liquid take the shape of its container?
Gas A gas -conforms to the shape of its container and fills the entire volume of its container. the particles of gases are very far apart. gases are easily compressed.
Physical Properties Characteristics that can be observed without altering the identity of the substance. (First observation) State, density, color, odor, melting point, boiling point, luster, conductivity, brittleness, malleability.
Chemical Properties Characteristics that cannot be observed without altering the identity of the substance. (Something turns into something else) Reactivity, flammability, reaction types
Similarly, the inability of a substance to change into another substance is also a chemical property. For example, when iron is placed in nitrogen gas at room temperature, no chemical change occurs. The fact that iron does not undergo a change in the presence of nitrogen is another chemical property of iron.
Physical Changes Physical Changes Do not alter the identity of a substance Crushing, tearing, changes of state (solid to liquid to gas) ** Dissolving a solid in liquid (reversible)** Can you think of any others?
Chemical Changes Chemical Changes Alter the identity or chemistry of a substance Burn, cook, rust, reacts with, explode, oxidize, corrode, tarnish, ferment, or rot: Terms that generally refer to a chemical reaction
Chemical Changes A chemical change is the same thing as a chemical reaction
The new substances formed in the reaction have different compositions and different properties from the substances present before the reaction occurred.
Here’s an example When a freshly exposed iron surface is left in contact with air, it slowly changes into a new substance, namely, the rust.
Rust is a chemical combination of iron and oxygen. In chemical reactions, the starting substances are called reactants and the new substances that are formed are called products.
So in the rusty nail problem, what are the reactants and what are the products? Reactants: Iron and Oxygen Product: Rust
Even though old substances become new substances, THE MASS STAYS THE SAME BEFORE AND AFTER THE REACTION!!!!
Conservation of Mass Mass is never created or destroyed by a reaction! It is conserved! (This is a LAW) The total mass in a reaction remains constant. Mass Reactants = Mass Products
How could you find this? Measure mass of reactants and mass of products and compare…they should be equal. Mass of the turkey, lettuce, mayo, tomato, and bread = mass of sandwich
Note Quiz Get out 1 piece of paper per table. Write both your names on it and work together! You will turn this in as a quiz grade.
Note Quiz Identify each of the following as a property of a solid, liquid, or gas. Some answers will include more that one state of matter. 1. Flows and takes the shape of a container 2. Compressible 3. Made of particles held in a tightly packed, specific arrangement
4. Has definite volume 5. Always occupies the entire space of the container 6. Has a definite volume but the particles flow 7. Phase change from solid liquid 8. Phase change from gas liquid
Notes Quiz Identify each of the following as an example of a chemical change or a physical change. 9. Moisture in the air forms beads of water on a cold windowpane. 10. An electric current changes water into hydrogen and oxygen