Table of Contents Measuring Matter Book K – Ch 1.1pgs 16-20 States of Matter Changes in Matter Gas Behavior Book K – Ch 1.1pgs 16-20 Book K – Ch 2.1 pgs - Book K – Ch 2.2 pgs 48-53 Book K – Ch 2.3 pgs -

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

Ch. 1 Sec. 2 “Measuring Matter” Book K – pgs 16-20 Volume - The amount of space that matter occupies. Common units of volume include the liter (L), milliliter (mL), and cubic centimeter (cm³). Volume = length x width x height The volume of an irregular object can be found by submersing it in water and calculating the change in water level. Density - The mass of a material in a given volume. Density = Mass Volume Measured in g/cm³ or g/mL Water has a density of 1 g/cm³

- Measuring Matter Calculating Density A small block of wood floats on water. It has a mass of 200 g and a volume of 250 cm3. What is the density of the wood? Read and Understand What information are you given? Mass of block = 200 g Volume of block = 250 cm3

Calculating Density - Measuring Matter A small block of wood floats on water. It has a mass of 200 g and a volume of 250 cm3. 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 cm3 = 0.80 g/cm3

Calculating Density - Measuring Matter A small block of wood floats on water. It has a mass of 200 g and a volume of 250 cm3. What is the density of the wood? Look Back and Check Does your answer make sense? The density is lower than 1.0g/cm3, which makes sense because the block can float.

Calculating Density Practice Problem - Measuring Matter 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

Calculating Density Practice Problem - Measuring Matter A piece of solid metal has a mass of 43.5 g and a volume of 15 cm3. What is the density of the metal? 2.9 g/cm3

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

More on Measuring Matter Click the PHSchool.com button for an activity about measuring 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

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

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.

Ch. 2 Sec. 2 “Changes of States” Book K pgs 48-53 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.

Ch. 2 Sec. 2 “Changes of States” Book K pgs 48-53 Changes Between Solid and Liquid 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

Ch. 2 Sec. 2 “Changes of States” Book K pgs 48-53 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

Ch. 2 Sec. 2 “Changes of States” Book K pgs 48-53 Changes Between Liquid and Gas 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.

Ch. 2 Sec. 2 “Changes of States” Book K pgs 48-53 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 CO2)

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.

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

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

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

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

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

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

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 (cm3), milliliters (mL), liters (L), and other units.

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

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.

Using Formulas - Gas Behavior Pressure can be calculated using the formula below. Force is measured in newtons (N). If area is measured in square meters (m2), 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 0.430 m2. What is the pressure in pascals on the piston? Pressure = 252 N/0.430 m2 = 586 Pa

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

Boyle’s Law - measures the volumes of gases at different pressures 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.

- Gas Behavior 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.

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

Book K Ch 2.3 pgs(55-61)-Measuring Gases Pressure and Temperature - Gas Behavior 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.

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 

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