What is the scientific method?
Make observations
Formulate a hypothesis
Test the hypothesis
What are the states of matter?
Solids, Liquids. Gases. Condensed Matter
What are some qualities of solids?
- Hard, fixed shape.
- Little volume changes with temperature changes.
- Particles are packed closely together in a regular array.
- They vibrate around their average position
- Very low compressibility
What are some qualities of liquids?
- Fluid, no fixed shape
- Fixed volume, little volume change with changes or temperature.
- Random orientation of the particles relative to one another
- They still stay close to one another
- Very low compressibility
What are some qualities of Gasses?
- Fluid, no fixed shape or volume
- Volume and pressure change dramatically with temperature changes
- Particles are far apart
- Particles move fast in a linear motion until they collide with another particle
- When kinetic energy is exchanged, the direction of motion changes.
- Very high compressibility
What are the rules of the Kinetic molecular theory?
- All particles are in motion
- The higher the temperature, the faster the motion
- The energy of the motion is called “kinetic energy”
- The kinetic energy is responsible for the temperature
What is matter?
Matter is anything that occupies space and has mass.
What is a heterogeneous mixture?
A mixture in which the composition is not uniform throughout the mixture.
What are some ways we can separate mixtures into their component pure substances?
- Filtration
- Distillation
- Chromatography
What is distillation?
The action of purifying a liquid by a process of heating and cooling.
What is Chromatography?
A chemical process of separating components of a mixture (think COVID test)
What is the formula to find density?
d= m/v
What is the difference between Extensive and Intensive Properties?
Extensive properties depend of the amount of substance: Mass, Volume
Intensive properties do not depend on the amount of substance: melting/boiling point, density.
What kind of property (extensive or intensive) is the following calculation: mass/volume = density. ?
intensive: The ration of two extensive properties is an intensive property.
List all the physical and chemical changes that occur between states of matter.
Solid- Liquid: Melting
Solid- Gas: Sublimation
Liquid- Gas: Vaporization
Gas- Liquid: Liquefaction
Liquid- Solid: Solidification
Gas- Liquid or Solid: Condensation
What is a chemical change?
There is a change in the identity of substances.
What are the two kinds of energy? What are they associated with?
1- Kinetic Energy - associated with motion
2- Potential Energy - associated with the position or status of objects
What are the different types of energy found within Kinetic energy?
- Thermal energy
- Mechanical energy
- Electrical energy
- Acoustic energy
What are the different types of energy found within Potential energy?
- Gravitational energy
- Electrostatic energy
- Nuclear energy
- Chemical energy
(GENC)
What is thermal energy?
motion of submicroscopic particles (atoms, ions, molecules): mostly vibrations and rotations
What is mechanical energy?
motion of macroscopic objects (balls, cars, people)
What is Electrical energy?
motion of electrons in conductors.
What is Acoustic energy?
pressure waves in materials (transmission of sound)
What is Gravitational energy?
attraction by very large bodies (Earth, Sun)
