Chemistry: the science that seeks to understand the behavior of matter by stuffing what atoms and molecules do.
Observation: Often the first step in the scientific method. An observation must measure or describe something about the physical world.
Theory: A proposed explanation for observations and laws. A theory presents a model of the way nature works and predicts behavior that extends well beyond the observations and laws from which it was formed.
Experiment: A procedure that attempts to measure observable predictions to measure a theory or law.
Law of Conservation of Mass: define
Differentiate between measured number and exact numbers
Exact numbers: have an unlimited number of sig figs
SI unit for :
Solve multistep conversion problems:???
Density: A fundamental property of materials that relates mass and volume and differs from one substance to another. The units of density are mass divided by volume: g/cm^3, g/mL, g/L…
Solid: atoms packed together on fixed locations giving them fixed volume and rigid shape.
2 forms of solid matter are crystalline solids and amorphous solids. crystalline solids: A type of solid matter with atoms and molecules arranged in a well- ordered, three-dimensional array with long-range, repeating order( e.g., salt and diamond) amorphous solids: A type of solid in which atoms or molecules do not have long range order( e.g. glass or plastic)
The particles in a liquid are closely packed, but they have some ability to move around.
•The close packing results in liquids being incompressible
•The ability of the particles to move allows liquids to take the shape of their container and to flow. However, they don’t have enough freedom to escape and expand to fill the container.
•In the gas state, the particles have complete freedom from each other.
•The particles are constantly flying around, bumping into each other and the container.
•In the gas state, there is a lot of empty space between the particles.
•Because there is a lot of empty space, the particles can be squeezed closer together. Therefore, gases are compressible.
•Because the particles are not held in close contact and are moving freely, gases expand to fill and take the shape of their container, and will flow.
(Chemical) composition of the substance
Ability of a substance to form new substances (chemical reactivity)
Properties other than composition and chemical reactivity
Temperature, speed, shape, physical state, color, etc.
•Chemical changes involve a change in the composition of the substance
–Produce a new substance
–Reactants → Products
–Example: burning wood
•Physical changes are changes that do not result in a change of the composition of the substance
–State changes: boiling, melting, condensing, etc.
–Change size, shape
•Example: chopping wood
Energy: The capacity to do work; PowerPoint answer: Ability of a system to do work on other physical systems
Potential energy is energy that is stored.
•Water flows because gravity pulls it downstream.
•However, the dam won’t allow it to move, so it has to store that energy.
Kinetic energy is energy of motion, or energy that is being transferred from one object to another.
•When the water flows over the dam, some of its potential energy is converted to kinetic energy of motion.
Convert energy units: joule, clorie, CALORIE, Kilowatt hour
Define edo and exo
K= °C + 273.15 AND °C = (°F – 32) / 1.8
Calculations for Q= mc(Tf – Ti)
Heat capacity is the amount of heat a substance must absorb to raise its temperature by 1 °C
•cal/°C or J/°C
•Metals have low heat capacities
•Insulators have high heat capacities
Specific heat = heat capacity of 1 gram of the substance
•cal/g°C or J/g°C
•Water’s specific heat = 4.184 J/g°C