Chemistry The Study of Matter

The Basics Chemistry is the study of matter and their interactions The substances of which physical substances are made The study of modern chemistry began in the 1700’s For thousands of years prior, alchemists were the main students of matter and their interactions Alchemy was a little science mixed with a lot of philosophy and spiritualism

Matter is classified based on its state or phase The 4 states/phases are: Solid Liquid Gas Plasma

Kinetic-Molecular Theory Describes solids, liquids and gases All matter consists of extremely small particles Particles are in constant, random motion The higher the temperature, the faster the particles are moving (more kinetic energy) The ‘energy of motion’

Solids Particles have lower kinetic energy than liquids (move at low speeds) Particles are close together and restricted to specific locations Particles are arranged with a high degree of regularity

Liquids Particles have a higher kinetic energy than solids (move at faster speeds) Particles are close to each other but can move past one another

Gases Particles have high kinetic energy (move at high speeds) Particles move freely in random, straight-line patterns Little interaction between particles

“Kinds” of Matter

Pure Substances Elements All atoms that make up an element are the same They exhibit unique chemical & physical properties They cannot be broken down into simpler substances All known elements are found on the periodic table

Can contain two or more different elements in a fixed proportion Compounds Can contain two or more different elements in a fixed proportion Exhibit unique chemical & physical properties Identified with chemical formulas Ex. H2O (water) CO2 (carbon dioxide)