Introduction to Matter Table of Contents Book K – Ch 1.1pgs Book K – Ch 2.1 pgs - Book K – Ch 2.2 pgs Book K – Ch 2.3 pgs - Measuring Matter States of Matter Changes in Matter Gas Behavior

Introduction to Matter Ch. 1 Sec. 2 “Measuring Matter” Book K – pgs International System of Units - The system of units (SI) used by scientists to measure the properties of matter. Weight - A measure of the force of gravity on an object. Mass - A measure of how much matter is in an object. Measured in units such as gram (g), kilogram (kg) Unlike weight, mass does not change with location, even when the force of gravity on an object changes.

Introduction to Matter Ch. 1 Sec. 2 “Measuring Matter” Book K – pgs 16-20

Introduction to Matter Calculating Density A small block of wood floats on water. It has a mass of 200 g and a volume of 250 cm 3. What is the density of the wood? Read and Understand What information are you given? Mass of block = 200 g Volume of block = 250 cm 3 - Measuring Matter

Introduction to Matter Calculating Density A small block of wood floats on water. It has a mass of 200 g and a volume of 250 cm 3. What is the density of the wood? Plan and Solve What quantity are you trying to calculate? The density of the block = ? What formula contains the given quantities and the unknown quantity? Density = Mass / Volume Perform the calculation. Density = Mass / Volume = 200 g / 250 cm 3 = 0.80 g/cm 3 - Measuring Matter

Introduction to Matter Calculating Density A small block of wood floats on water. It has a mass of 200 g and a volume of 250 cm 3. What is the density of the wood? Look Back and Check Does your answer make sense? The density is lower than 1.0g/cm 3, which makes sense because the block can float. - Measuring Matter

Introduction to Matter Calculating Density Practice Problem A sample of liquid has a mass of 24 g and a volume of 16 mL. What is the density of the liquid? 1.5 g/mL - Measuring Matter

Introduction to Matter Calculating Density Practice Problem A piece of solid metal has a mass of 43.5 g and a volume of 15 cm 3. What is the density of the metal? 2.9 g/cm 3 - Measuring Matter

Introduction to Matter Density Click the Video button to watch a movie about density. - Measuring Matter

Introduction to Matter More on Measuring Matter Click the PHSchool.com button for an activity about measuring matter. - Measuring Matter

Introduction to Matter Ch 2.1 “States of Matter” - Solids The three main states of matter are solids, liquids, and gases. They can be found in nature as elements, compounds, or mixtures. Solid has a definite shape and a definite volume. A result of closely packed arrangement of particles Two types of solids: crystalline and amorphous Crystalline solids – are made up of atoms that form regular repeating patterns (crystals) Ex: salt, sugar, and snow Amorphous solids – have the particles are not arranged in a regular pattern. Ex: plastics, rubber, and glass

Introduction to Matter Ch 2.1 “States of Matter” - Liquids Liquids - have a definite volume but no shape of its own A result of particles are free movement Liquid is a fluid (a substance that flows.) Surface tension – the result of an inward pull among the molecules of a liquid that brings the molecules on the surface closer together. Ex: water droplets pulling together on a smooth surface Viscosity - a liquid’s resistance to flowing. Honey = high viscosity; Water = low viscosity

Introduction to Matter Ch 2.1 “States of Matter” - Gases Gases – are fluids that can change shape and volume As they move, gas particles spread apart, filling all the space available.

Solids, Liquids, and Gases Ch. 2 Sec. 2 “Changes of States” Book K pgs Changes Between Solid and Liquid Melting – The change in state from a solid to a liquid. In pure substances it occurs at an exact temperature called the melting point. Melting point of pure water = 0ºC Energy (heat) that is added to the stationary molecules cause them to vibrate. At melting point, the particles of a solid substance are vibrating so fast that they break free from their fixed positions.

Solids, Liquids, and Gases Ch. 2 Sec. 2 “Changes of States” Book K pgs Changes Between Liquid and Solid Freezing – The change of state from liquid to solid At its freezing point, the particles of a liquid are moving so slowly that they begin to form regular patterns Freezing point of pure water = 0ºC

Solids, Liquids, and Gases Ch. 2 Sec. 2 “Changes of States” Book K pgs Changes Between Liquid and Gas Vaporization – change from liquid to gas Liquid particles gain enough energy to form a gas Two types – evaporation and boiling Evaporation – vaporization that takes place on the surface of a liquid Boiling – vaporization both at and below the surface Boiling point – temperature at which liquid boils Is dependent on air pressure – the lower the pressure, the less energy is needed to make the molecules boil Ex: Sea Level – water boils at 100ºC; Denver (1600m) – water boils at 95ºC

Solids, Liquids, and Gases Ch. 2 Sec. 2 “Changes of States” Book K pgs Changes Between Gas and Liquid Condensation – change from gas to liquid Occurs when particles in a gas lose enough thermal energy to form a liquid Ex: Clouds NOTE: Water vapor is invisible. Clouds, Fog, and Steam are all liquid droplets of water suspended in the air.

Solids, Liquids, and Gases Ch. 2 Sec. 2 “Changes of States” Book K pgs Changes Between Solid and Gas Sublimation – occurs when particles of a solid gain enough energy that they form a gas They do not pass through a liquid state Ex: Dry ice (frozen CO 2 )

Solids, Liquids, and Gases Temperature and Changes of State A beaker of ice at – 10ºC was slowly heated to 110ºC. The changes in the temperature of the water over time were recorded. The data were plotted on the graph shown here. - Changes of State

Solids, Liquids, and Gases Temperature and Changes of State Temperature (ºC) on the y- axis, time (minutes) on the x- axis Reading Graphs: What two variables are plotted on the graph? - Changes of State

Solids, Liquids, and Gases Temperature and Changes of State The temperature is rising from 0ºC to 100ºC. Reading Graphs: What is happening to the temperature of the water during segment C of the graph? - Changes of State

Solids, Liquids, and Gases Temperature and Changes of State Segment B: melting point of ice; segment D: boiling point of water Interpreting Data: What does the temperature value for segment B represent? For segment D? - Changes of State

Solids, Liquids, and Gases Temperature and Changes of State Change from solid to liquid; change from liquid to gas Drawing Conclusions: What change of state is occurring during segment B of the graph? For segment D? - Changes of State

Solids, Liquids, and Gases Temperature and Changes of State Water molecules in segment E have more thermal energy because they are at a higher temperature. Inferring: In which segment, A or E, do the water molecules have more thermal energy? Explain your reasoning. - Changes of State

Solids, Liquids, and Gases Data Sharing Lab Click the PHSchool.com button for an activity about sharing data for the Skills Lab Melting Ice. - Changes of State

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Gases can easily contract or expand. When working with a gas, it is helpful to know its volume, temperature, and pressure. When gases, such as helium are pressed tightly together (compressed), the volume decreases. Volume- the amount of space that matter fills. Volume is measured in cubic centimeters (cm 3 ), milliliters (mL), liters (L), and other units.

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Temperature- a measure of the average energy of random motion of the particles of a substance. Increased speed = Increased energy = Increased temp Ex. The faster you rub your hands together, the warmer they become

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Particles are constantly colliding with one another, and in a gas, they are also colliding with the walls of their container When you push on a wall, you are applying pressure Pressure- the force of the outward push of a gas divided by the area of the walls of the container Ex. A punctured basketball deflates as gas particles begin to escape.

Solids, Liquids, and Gases Using Formulas Pressure can be calculated using the formula below. Force is measured in newtons (N). If area is measured in square meters (m 2 ), pressure is expressed in pascals (Pa). Pressure = Force / Area For example, a machine exerts a force of 252 N on a piston having an area of m 2. What is the pressure in pascals on the piston? Pressure = 252 N/0.430 m 2 = 586 Pa - Gas Behavior

Solids, Liquids, and Gases Using Formulas Practice Problem A trash compactor exerts a force of 5,600 N over an area of m 2. What pressure in pascals does the compactor exert? P = 5,600 N/0.342 m² = 16,374 Pa - Gas Behavior

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Pressure and Volume: Boyle’s Law Boyle’s Law - measures the volumes of gases at different pressures Named after Robert Boyle Found that when the pressure of a gas at a constant temperature is increased, the volume of the gas decreases. When the pressure is decreased the volume increases. This relationship between pressure and volume of a gas is known as Boyle’s law.

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Pressure and Volume: Boyle’s Law As weights are added, the gas particles occupy a smaller volume. The pressure increases. - Gas Behavior

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Pressure and Temperature Remember….heat = energy = movement The faster gas particles move, the more frequently they collide with the walls of their container and the greater the force of their collisions When the temperature of a gas at a constant volume is increased, the pressure of the gas increases. When the temperature is decreased, the pressure of the gas decreases. Temperature  (and volume stays same) = Pressure  Constant volume can occur in a closed ridged container

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Pressure and Temperature When a gas is heated, the particles move faster and collide more often with each other and with the walls of their container. The pressure of the gas increases. - Gas Behavior

Solids, Liquids, and Gases Book K Ch 2.3 pgs(55-61)-Measuring Gases Volume and Temperature: Charles’s Law Jacques Charles – experimented with hydrogen balloons. He kept pressure constant and observed the changes temperature had on volume. Charles’s Law - When the temp of a gas is increased at constant pressure, its volume increases. When the temp of a gas is decreased at constant pressure, its volume decreases. Temperature  (and pressure stays same) = Volume 

Solids, Liquids, and Gases Gas Laws Activity Click the Active Art button to open a browser window and access Active Art about gas laws. - Gas Behavior