Chapter 3 - Matter and Energy Flashcards
Physical Properties of Matter
do NOT involve change in composition
ex) odor (gas does not change property)
Chemical Properties of Matter
involve a change in composition
- corrosiveness, flamability, acidity, toxicity
ex) flammability (gas changed composition when it burns)
Physical Change
he appearance of matter may change, but its composition does not
- state change
- results in a different form of the same substance
ex) water vapor to liquid form
Chemical Change
the composition of matter change
-results in a completely new substance
ex) iron can rust (iron to iron oxide)
Conservation of Mass
- matter is always conserved,
- the sum of mass reactants must equal the sum of masses of the products
ex) AB=A+B
Energy
energy is conserved, it can be neither created not destroyed
-capacity to do work
-units are joule (J), calorie (cal), nutritional calorie (Cal), and kilowatt-hour (kWh)
Exothermic
chem rxn that emit energy
Endothermic
chem rxn that absorb energy
Temperature
-related to random motions of the molecules and atoms
Temperature -
3 Scales of Measurement
1 Fahrenheit (F) 2 Celsius (C) 3 Kelvin (K)
Heat Capacity
temp that change the matter undergoes upon absorption of heat is related to the heat capacity of the substance composing the matter
States of Matter
1 Liquid
2 Gas
3 Solid (Amporphous or Crystalline)
Classification of Matter
Pure matter or Compound
Pure Matter
an element (cannot be decomposed into a simpler substance)
Compound
a substance composed of 2 or more elements in fixed definite proportions
Mixtures
2 or more different substances
-proportion of which may vary from one sample to the next
Homogeneous Mixture
having the same composition throughout
Heterogeneous Mixture
having a composition that varies from region to region
Molecule
2 or more elements joined together
Substance
a catch all word for molecule, element, or comb of moles and elements.
Solid Matter
- atoms or moles pack close to each other in fixed positions
- neighboring atoms/moles may vibrate or oscillate but they do not move around each other
- has fixed vol, rigid shape
Crystalline Solid
atoms/moles are arranged in geometric patterns w long-range, repeating order
ex) salt and diamond
Amorphous Solid
atoms/moles DO NOT have long-range order
ex) glass, rubber, plastic
Liquids
atoms/moles are close to each other but are free to move around
- assume the shape of their containers
- fixed volume