Chapter 16 Study Guide Four States of Matter Solids – low KE - particles vibrate but can’t move around – atoms held tightly into place – definite shape & volume Four States of Matter Liquids – higher KE - particles can move around but are still close together – no definite shape – definite volume Four States of Matter Gases – high KE - particles can separate and move throughout container – no definite shape & volume – move more quickly than particles that make up solids Four States of Matter Plasma – very high KE – made up of charged particles (+/-) – gas-like, indefinite shape & volume – most common state of matter – stars Pressure • Pressure is the amount of force exerted per unit of area, or P = F/A. • Pressure is measured in a unit called Pascal (Pa), the SI unit of pressure. • Most matter expands when heated. Heating Curves Heat of Fusion – energy required to change from solid to liquid – some attractive forces are broken Heating Curves Heat of Vaporization – energy required to change from liquid to gas – all attractive forces are broken Archimedes’ Principle Archimedes - Whether an object will sink or float in a fluid Viscosity – Resistance to flow by a fluid Archimedes’ Principle Archimedes’ Principle – the buoyant force on an object in a fluid is equal to the weight of fluid displaced by the object Not More water needs water is to displaced betodisplaced in order in order cancel to to Veryenough little water needs be displaced intoorder cancel weight weight ball sinks. ball floats lower in the water. on surface. View Buoyancy JAVA Applet. View animations produced by students at Poly Prep Country Day School in Brooklyn, New York. Archimedes’ Principle Buoyant Force – upward force exerted by a fluid on an immersed object – buoyant force > weight balloon rises – buoyant force < weight balloon sinks – buoyant force = weight balloon floats Charles’ Law • According to Charles’s law, the volume of a gas increases with increasing temperature, (at constant pressure) V1 V2 T1 T2 V T DIRECT Pascal’s Principle Pascal’s Principle – pressure applied to a fluid is transmitted unchanged throughout the fluid Pascal - hydraulics F1 F F2 P A1 A A2 Boyle’s Law When the volume of a gas decreases, its pressure increases (at constant temp). • As the volume is increased, the pressure will decrease. P V INVERSE P1V1= P2V2 Bernoulli’s Principle Bernoulli’s Principle – as the velocity of a fluid increases, the pressure exerted by the fluid decreases – why planes fly Thermal Expansion When concrete absorbs heat, it expands. Then when it cools, it contracts. If expansion joints are not used, the concrete will crack when the temperature changes. Charles’ Law •If you place a balloon in a freezer the molecules will slow down and the balloon will shrink as the volume decreases Charles’ Law Absolute Zero - Temp at which... – the volume of a gas would equal zero. – all particle motion would stop. -273°C or 0 K