Studied by 2 people
Chemistry
Science studying matter's behavior and properties.
Matter
Anything with mass and occupies space.
States of Matter
Solid, liquid, gas based on physical state.
Solid
Definite shape and volume.
Liquid
Definite volume, shape of container.
Gas
No definite shape or volume; expands.
Pure Substance
Fixed composition, made of one component.
Mixture
Combination of two or more pure substances.
Homogeneous Mixture
Uniform appearance and composition throughout.
Heterogeneous Mixture
Distinct regions with different compositions.
Element
Cannot be chemically broken into simpler substances.
Compound
Contains two or more elements in a definite ratio.
Intensive Property
Independent of the amount of substance present.
Extensive Property
Varies with the amount of substance present.
Physical Property
Observable characteristics without changing composition.
Chemical Property
Describes behavior during composition change.
Physical Change
No change in composition; only physical state changes.
Chemical Change
Composition of matter changes; new substances formed.
Separation of Mixtures
Using physical methods based on component properties.
Filtration
Separation technique using a barrier to separate solids.
Distillation
Separation based on differences in boiling points.
Chromatography
Technique for separating components based on movement.
Odor of paint thinner
Characteristic smell from volatile organic compounds.
Ozone decomposition
Breakdown of ozone by ultraviolet light exposure.
Silver shine
Luster from polished silver surface.
Iron rust tendency
Iron's susceptibility to oxidation and corrosion.
Boiling point of ethyl alcohol
Temperature at which ethyl alcohol vaporizes, 78.37°C.
Flammability of ethyl alcohol
Ability of ethyl alcohol to ignite and burn.
Physical change
Change affecting form, not chemical composition.
Chemical change
Change resulting in new chemical substances.
Scientific method
Systematic approach for scientific investigation.
Observations
Data describing nature's characteristics or behaviors.
Hypothesis
Tentative explanation based on observations.
Scientific law
Statement summarizing observed phenomena consistently.
Theory
Explanation of phenomena based on experimental validation.
Law of conservation of mass
Matter is neither created nor destroyed in reactions.
Law of definite proportions
Compounds have consistent elemental composition ratios.
Law of multiple proportions
Different compounds from same elements have simple ratios.
Atomos
Term for indivisible particles proposed by ancient philosophers.
Dalton's atomic theory
Theory stating matter consists of indivisible atoms.
Chlorine reactivity
Observation noting chlorine's high reactivity as a gas.
Matter composition
All matter consists of particles called atoms.
Chemical reaction matter conservation
Total mass remains constant during chemical reactions.
Law of Definite Proportions
Mass ratio of elements in a compound is constant.
Decomposition of Water
18.0 g of water yields 16.0 g O2 and 2.0 g H2.
Oxygen-to-Hydrogen Ratio
Mass ratio of oxygen to hydrogen is 8:1.
Law of Multiple Proportions
Mass ratios of elements in compounds are whole numbers.
John Dalton
Published the law of multiple proportions in 1804.
Carbon Compounds Example
Carbon monoxide and dioxide illustrate multiple proportions.
Dalton's Atomic Theory
Atoms are indivisible and combine in fixed ratios.
Atomic Indivisibility Question
Are atoms composed of smaller particles?
Cathode Rays
Particles traveling from cathode to anode in experiments.
Properties of Cathode Rays
Travel in straight lines and carry negative charge.
Thomson's Charge-to-Mass Ratio
e/m = -1.76 × 10^8 Coulomb/g.
Millikan's Oil Drop Experiment
Measured electron charge and determined its mass.
Electron Charge
Charge of electron is -1.60 × 10^-19 C.
Mass of Electron
Mass of electron is 9.10 × 10^-28 g.
Thomson's Plum-Pudding Model
Electrons embedded in a positively charged sphere.
Radioactivity
Spontaneous emission of radiation discovered by Becquerel.
Types of Radiation
Alpha, beta, and gamma rays are radiation types.
Alpha Rays
Positively charged helium nuclei emitted during radioactivity.
Beta Rays
Negatively charged electrons emitted during radioactivity.
Gamma Rays
Neutral high-energy radiation emitted during radioactivity.
Rutherford's Gold Foil Experiment
Demonstrated nuclear structure of the atom.
Nuclear Model of Atom
Atom's mass and positive charge concentrated in nucleus.
Electron
Negatively charged particle outside the nucleus.
Proton
Positively charged particle in the nucleus.
Neutron
Neutral particle within the nucleus.
Atomic Number (Z)
Number of protons in an atom's nucleus.
Mass Number (A)
Total of protons and neutrons in an atom.
Isotope
Atoms with same protons, different neutrons.
Natural Abundance
Percentage of each isotope in a sample.
Cation
Positively charged ion from losing electrons.
Anion
Negatively charged ion from gaining electrons.
Atomic Mass
Average mass of an element's isotopes.
Mass Spectrometry
Technique for measuring atomic masses and isotopes.
Mole
SI unit for amount of substance, 6.022 x 10^23.
Molar Mass
Mass of one mole of atoms in grams.
Atomic Symbol
One or two letters representing an element.
Berzelius
Inventor of symbols for chemical elements.
Subatomic Particles
Particles smaller than atoms: protons, neutrons, electrons.
Element
Substance defined by its unique number of protons.
Neutral Atom
Atom with equal numbers of protons and electrons.
Relative Atomic Mass
Weighted average of isotopes' masses in a sample.
Chemical Notation
Symbol followed by mass number for isotopes.
Avogadro's Number
6.022 x 10^23, number of entities in a mole.
Rutherford's Model
Early atomic model emphasizing nucleus and electrons.
