Chemistry (Complete)

• Chemistry: The study of composition, structure, properties and reaction of matter.
• Sciences related to chemistry: Mathematics, physics, biology, medicine and engineering
• Pure substance: Matter that has fixed or definite composition.
• Mixture: Two or more different substances are physically mixed but not chemically combined.
• Elements and compounds are the two kinds of pure substances
• Element: Composed of only one type of atom, cannot be broken down into simpler substances.
• Compound: Consists of atoms of two or more elements.
• Heterogeneous mixture: The components do not have a uniform composition throughout the sample.
• Homogeneous mixture: The composition is uniform throughout the sample.
• These are separation methods for homogeneous mixtures: Filtration Crystallization Distillation and Chromatography
• These are separation methods for heterogeneous mixtures: Filtration, handpicking and sieveing
• Chemical: Substance that always has the same composition and properties whenever it is found.
• Physical properties are those characteristics that can be observed or measured without affecting the identity of a substance
• Physical properties of matter: Shape, color, melting point, boiling point and physical state of a substance.
• Physical change: A change in a physical property that retains the identity of the substance.
• Chemical property: A characteristic that indicates the ability of a substance to form another substance.
• Chemical change: A change in which the original substance is converted to one or more new substances.
• These are the three states of matter: Solid, liquid and gas
• A solid has a definite shape and volume.
• In a solid, the particles are close together and vibrate around a fixed position.
• In a solid, it has a definite shape and volume, the particles are very close, the interaction is very strong, and the movement is very slow.
• In a liquid, it takes the shape of the container, has a definite volume, the particles are random and close, the interaction is strong and the movement is moderate.
• In a gas, it takes the shape of the container, it fills the volume with the container, the particles are random and far apart, essentially none interaction between particles and their movement is very fast.
• Melting is the physical change of matter.
• The melting point is the point at when the materials change to a liquid, which is defined by the temperature.
• Is a diagram that shows all the changes of state that take place in a substance as heat is added.
• These are non-renewable resources that can be used to obtain energy: Coal, natural gas and oil
• These are 3 sources to obtain clean energies: Wind power, solar power and bioenergy
• Kinetic energy is the energy of motion.
• Potential energy is determined by the position of an object or by the chemical composition of a substance.
• Chemical energy is the energy that is stored in the bonds of chemical compounds (molecules and atoms)
• Nuclear energy is the form of energy released from the nucleus to the core of atoms.
• Thermal energy is the energy contained within a system that is responsible for its temperature.
• Luminous energy is energy emitted or propagated in the form of light.
• Electrical energy is the type of kinetic energy caused by moving electric charges..
• Sublimation is the change from solid to gas.
• Deposition is the change from gas to solid.
• Condensation is the change from gas to liquid.
• Evaporation is the change from liquid to gas.
• Freezing is the change from liquid to solid.