Science PDF - Mixtures, Substances, and Elements

Unit 2 Read Textbook chapters 3.2, 3.3, & 4.1 Mixtures, Pure - Pure substance is made up of only one kind of molecule Substances and and cannot be broken down via physical means Elements - Element: Primary component of matter...

Unit 2 Read Textbook chapters 3.2, 3.3, & 4.1 Mixtures, Pure - Pure substance is made up of only one kind of molecule Substances and and cannot be broken down via physical means Elements - Element: Primary component of matter - Cannot be broken down chemically any further until you're just breaking apart atoms - Periodic table - Iron - Gold - Titanium - oxygen - Compound: Made of two or more elements combined chemically - Can be chemically broken down into simpler substances (elements) - Ex. H2O is water - bronze Mixtures are two or more pure substances combined physically - Homogenous mixture: Uniform composition, one phase/layer, hard to separate - Alloy - a mixture of 2 or more metals (brass, steel, 14k gold) - Solution - Mixture of solids/liquids/gases dissolved into each other (saltwater, no seawater, tea, alloys) - Heterogenous mixture: Non-uniform composition, more than one phase, easier to separate - Colloid - can only be identified by looking through bba microscope (milk, jello, fog) - Suspension - two substances mix initially but then separate over time (muddy water, oil, and water) Miscibility: The ability of two or more liquid substances to be mixed and dissolve into one another - Miscible = homogenous - Immiscible = heterogenous Atoms are single neutral particles Molecules are neutral particles made of two or more atoms bonded together Seperation of mixtures Elements cannot be separated Compounds can be separated chemically Mixtures can be separated physically Seperation techniques for mixtures - Distillation - miscible liquids based on their different boiling points - Centrifugation - colloids based on densities - Paper chromatography - dyes and inks based on how fast they diffuse through an apparatus - Magnetism - magnetic and non-magnetic substances - Filtration - separates solids from liquids in a heterogenous mixture - Evaporation/vaporization - separates solids dissolved in liquids in a homogenous mixture - Manual separation - separating by hand Minerals Minerals are chemical compounds that occur naturally in their solid form on Earth Rocks are naturally occurring combinations of several minerals (heterogeneous mixtures)