All about matter ; SCIENCE

• all materials are made up of a "primal matter"
• According to thales it was water, Anaximenes it was air, to Heraclitus it was fire
• But for Aristotle it was air, earth, water, and fire
• Atom - tiny bits of matter that cannot be divided
• Matter - classified into substances and mixtures
• Substances - includes elements and compounds
• Element - simplest substance, contains only one atom
• Compound - made up of two or more elements that are chemically combined
• Mixtures - are not pure substances, always consists of two or more substances
• Physical change - change in one or more physical properties
• Endothermic - heat energy is absorbed
• Exothermic - heat energy is released
• Phase change - process of changing from one physical state of matter to another
• Melting - Solid to liquid
• Evaporation - Liquid to gas
• Sublimation - Solid to gas
• Condensation - Gas to liquid
• Freezing - Liquid to solid
• Deposition - Gas to solid