Final Exam Notes

Unit 1: Matter, Transformation, and Energy

• Chemistry: The study of properties of materials and the changes the materials undergo
• Matter- Anything that occupies space and has mass. We can classify it based on:
• The State of Matter: Solid, Liquid, or Gas
• Solids and liquids are referred to as the condensed phases. 
• Gases have different characteristics than the latter. 
• What state a material is in depends largely on two factors:
• The amount of kinetic energy the particles possess
• The strength of attraction between the particles, potential energy (inter molecular forces)
• A change in state is a physical change where the physical form changes but keeps its composition.
• Reversible by changing the temperature.
• Solids: 
• High potential energy and low kinetic energy. 
• The only motion is vibration of the atoms and molecules. 
• Definite shape and volume.
• Liquids:
• Attraction between atoms is still high but it has higher kinetic energy and lower potential energy
• definite volume but not definite shape for it takes up the shape of the container. 
• Vibration, rotation, and some translation
• Gas:
• There is little attraction between the atoms
• High kinetic energy, low potential energy
• Vibration, rotation, and lots of translation
• The Composition of Matter: 
• Matter is either a mixture or substance.
• Substance: form of matter with definite composition and distinct properties. 
• Elements: A pure substance that cannot be chemically converted into a simpler substance. Consists of Atoms or Elements. 
• Atoms: Any no diatomic elements; Atoms are the building blocks of matter and they combine to make molecules.
• Molecule: Any Diatomic element (elements that only occur in pairs in nature)
• Br2,  I2, N2, Cl2, H2, O2, F2
• A chemical combination of two or more atoms
• Compounds: elements can combine with other elements to form compounds
• Mixture: physical combination of two or more substances.
• homogeneous: uniform throughout
• heterogeneous: NOT uniform throughout
• Physical Change:
• A change that occurs without changing the molecular composition. The same element is present before and after.
• Ex. Water is the same no matter if it is liquid or solid (ice).
• Examples of physical properties:
• Mass, volume, color, solid, texture, smell, taste, ect.
• Extensive Properties: Properties that depend of the amount of a substance (mass, volume)
• Intensive Properties: Does not change with the amount of a material (density, specific heat, melting and boiling points)
• Chemical Change:
• The property's potential to undergo change to form a different product. 
• Results of a bonds breaking in the reactants and rearrangements of the atoms to different substances (s). 
• Combustible, corrosive, toxic, flammable
• indicated by temp., color, bubble and precipitate formation
• The Atomic Theory of Matter
• Define Laws of Chemistry:
1. Law of Mass Conservation: In a chemical reaction, matter is neither created not destroyed. 
• The combined masses of the reactant must equal combined masses of the product
2. Law of Definite Proportions/ Law of Definite Composition:
• All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements. 
3. Laws of Multiple Proportions (John Dalton):
• The ratio of the two masses is a small whole number
• John Dalton's Atomic Theory:
1. Each element is composed of elements
2. Each element is composed of only one type of atom
3. Compounds are formed when atoms of more than one element combine in simple, whole number rations (ex. H2O)
4. Atoms of an element are not changed into atoms of different element by chemical reactions
• John Dalton:
• Modern atomic theory

The Discovery of the Electron:

• JJ Thomson: Discovered the Electon 
• Cathode Ray Tubes: A high voltage passed through a partially evacuated glass tube, produced radiation

Robert Millikan Experiment: 

• Oil drop experiment
• Find out charge of electron (1.6X10^-19)

The Discovery of Atomic Nucleus:

• Ernest Rutherford: Gold Foil Experiment; discovered the mystery of how electrons fit inside the atom
• Used beams of particles as projectiles to explore the structure matter
• Discovered nucleus and it is contents: protons and neutrons.

• Atoms are composed of three subatomic particles: protons, neutrons, and electrons that effect the chemical behavior of an atom.

Protons and neutrons reside in the nucleus of the atom (held together by strong nuclear force) while the area surrounding the nucleus is a diffused region of negative charge where the electrons reside.

• An atom must have the correct ratio of protons and neutrons for stability. 
• Protons: The number of protons in the nucleus in the nucleus is called the atomic number (Z) and determines the identity of the atom 
• Neutrons: neutral
• Electrons: Same number as protons