Presentation on theme: "Chapter 17 Study Guide. Matter Matter is classified as substances and mixtures. Matter has mass and takes up space Mixture – composition variable, can."— Presentation transcript:
Chapter 17 Study Guide
Matter Matter is classified as substances and mixtures. Matter has mass and takes up space Mixture – composition variable, can be separated by a physical means Element – composition definite Compound – two or more elements combined
Pure Substances Element matter composed of identical atoms All atoms are the same EX: copper
Classifying Matter Colloid vs. Solution-pass a beam of light through the mixture If the beam is invisible- it is a solution If the beam is visible- it is a colloid The visible beam through the colloid is called the Tyndall effect Suspension- heterogeneous mixture containing a liquid in which visible particles settle out over time – like dirty water and Italian salad dressing
Mixtures Variable combination of 2 or more pure substances. Homogeneous Mixture (AKA -Solution) even distribution of components very small particles particles never settle EX: saline solution, fresh pickle juice
Mixtures Heterogeneous Mixture uneven distribution of components colloids and suspensions EX: granite
Pure Substances Compound matter composed of 2 or more elements in a fixed ratio properties differ from those of individual elements NOT a mixture EX: salt (NaCl)
Tyndall Effect Because of the Tyndall effect, A light beam is Scattered by the Colloid suspension On the right, but Passes invisibly Through the solution On the left.
Physical Properties Physical Property- any characteristic of a material that you can observe or attempt to observe without changing the identity of the substance For example: color, shape, size, melting point, and boiling point, how it flows. Metallic aluminum: Silvery color, easily formed, reflects heat. Behavior of substances- magnetism, ductility- ability of metal to be drawn into wires; malleability- ability of metal to be shaped- pounded into sheets; ability to flow
Physical Change A change in the form of a substance without changing its identity. properties remain the same reversible can be used to separate mixtures EX: dissolving, grinding, distillation, mixing sugar and salt
Physical Changes Distillation- separating a solution of two liquids through evaporating a liquid and re-condensing its vapor. Vapors from the liquid with the lowest boiling point form first and are condensed and collected
Chemical Property A characteristic that indicates whether a substance can undergo a specific chemical change. EX: flammability, reactivity, resistance of a diamond to corrosion Chemical changes can be used to separate substances- done in labs- metals can be removed from ore this way
Chemical and Physical Weathering Weathering- Physical weathering when rocks split as water freezes or as erosion occurs Chemical weathering when acidic water reacts with limestone and results in a new substance that dissolves in water and washes away.
Law of Conservation of Mass Mass cannot be created or destroyed Burning a log seems to make mass disappear “missing” mass is actually present in the gases that are produced as the log burns When the log burns new substances are formed. EX: Iron and oxygen combining to form rust, the masses will still be equal.