What Is Everything Made of? If it has mass and volume it’s… MATTER!
What Is Not Matter. • Energy (heat, light, electricity, etc). • Forces (gravity magnetism and the nuclear forces) • Space itself is a 3-D “fabric” but not matter.
Law of Conservation of Mass. • Matter cannot be created nor destroyed, except in a nuclear reaction when it becomes energy E=mc2. • A burning log does not disappear, collect all the smoke and ashes and the mass is the same.
Mass is a Measure of the Amount of Matter • Mass is measured with a triple beam balance. • Mass is measured in grams (g), a gram is the mass of 1cm3 of water and is about the mass of a paperclip • 1000g = 1 kilogram (kg)
Volume • Volume = measure of the amount of space a piece of matter occupies. • 1 milliliter (mL) = 1cm3 • mL is used for liquids, cm3 is always right • 1000mL = 1 liter (L)
Measuring Volume • Use a graduated cylinder for liquids. • Measure at the bottom of the meniscus • Use an overflow can for oddly shaped objects
Measuring • Measure to 2 decimal places with a ruler or triple beam balance • Measure to 1 decimal place with a graduated cylinder. • Last number is always a guess. • When calculating, your answer can never have more decimals than your data.
Estimate the volume of each example • 82.7 mL • 58.0 mL • 52.2 mL
You need this handout. • 4.53 • 8.10 • 2.45 • 6.06 • 0.86 • 8.04 • 5.00
Dihydrogen Monoxide • Tare a container then measure mass every 10mL up to 60mL. Graph your data • If you are accurate it will form a line, the more accurate you are, the closer your data will be to a line. • When real scientists do an experiment, their hope is their data will form a line or curve. • Draw the line of best fit. Be sure to go through (x=0,y=0)
All Matter has Gravity • The elephant has more matter so it has more mass and more gravity. • Even dust is matter so it has gravity.
The cause of gravity remains mysterious. • It just never gives up. • Einstein described gravity as matter warping the fabric of space. • Quantum physics predicts a particle (graviton) could exist, but one has never been found.
Gravity Decreases With Distance • As a square • So it drops off quickly to next to nothing
Gravity isn’t the same everywhere on the Earth • Gravity at any location depends upon many factors such as the makeup and thickness of the crust • Imagine two gravity meters, the one on the ground is closer to the center of the Earth so it reads higher.
Weight is the Pull of Gravity • Weight is a measure of the pull of gravity. • Weight is measured with a spring that is compressed or stretched.
How can something be nothing? • Far enough from the pull of a planet, an astronaut could become weightless. • The astronaut and the space suit are made of something… • but, according to weight they are nothing, which is impossible!
Another Problem • Weight changes when you’re standing on a different planet or on the moon • The Earth’s mass is six times the moons. • On Earth the astronaut weighs 185 lbs. • Moon has 1/6th the gravity so the astronaut weighs only 31 lbs. • Weight is not about the astronaut, it’s about what object they’re standing on.
Weight changes in many situations. When an elevator drops downward. At the top of the roller coaster’s hill. When an airplane flies a parabolic arc. Skiers “unload” (flex downward at the knees) to reduce the effects of weight.
Mass is a Comparison • Mass is measured with balance, it works like a teeter totter. • Something is placed on one side a pumpkin. • Something else is placed on the other side till it balanced. • In the metric system everything is compared to water.
Mass Does Not Change • While on the Earth I will place an object on one side of a balance and an equal amount of water on the other side. • Now I will travel to the moon. • Once on the moon I will repeat the experiment. • Although the moon pulls 1/6th as hard on the object, it also pulls 1/6th as hard on the water, so it still balances.
Measuring Mass in Space • All objects that have mass resist a change in motion (inertia) • The more mass the more it resists moving. • The space station uses a chair, that the astronaut must rock back and forth
Volume of Rectangular Objects • Measure length, width and height in centimeters (cm) • Multiply length x width x height • Example: A block is 10 cm long, 2 cm wide and 3 cm tall. • Its volume is 10 cm x 2 cm x 3 cm = 60 cm3
D = m/v • Denser things sink. • The density of pure water is 1.0 g/cm3 by definition. • Anything denser sinks; anything less dense floats. • Saltwater is denser than fresh. • Density can be used to identify substances.
Example: An object has a mass of 200.00g and a volume of 340.00 cm3. What is its density and will it sink or will it float? • D=m/v • D= 200.00g/340.0 cm3 • D=0.6g/cm3 • It will float because it’s density is less than 1.0 g/cm3
Significant digits • When you do operations (add, subtract, multiply, divide) your answer can only have as many significant digits as your weakest data • Numbers 1-9 are always significant • Zeros between numbers are always significant, but for zeros before
Example 2: A graduated cylinder starts with 45.12 mL of water. An object with a mass of 12.30g is lowered into the water. The water in the cylinder goes up to 56.78 mL. What is the density of the object? • Volume = 56.78mL - 45.12 mL • Volume = 11.66 ml • D= m/v • D= 12.30g/11.65cm3 • D=1.16g/cm3 (we only get to keep 1 decimal)
All your measurements will be in cm. • Your measurements must have 2 decimal places
What is density? • Density is a comparison of how much matter there is in a certain amount of space. • How big something is compared to how heavy it is.
Density explains why: • hot air balloons take off before dawn. • very light sand grains sink, while very heavy aircraft carriers float. • the Earth has layers, and why land rises and sinks. • we can separate things like crude oil into its parts (gasoline, diesel, etc.).
Liquid Layers • If you pour together liquids that don’t mix and have different densities, they will form liquid layers. • The liquid with the highest density will be on the bottom. • The liquid with the lowest density will be on the top.
Liquid Layers • Imagine that the liquids have the following densities: • 10g/cm3. 3g/cm3. • 6g/cm3. 5g/cm3. • Which number would go with which layer?
Liquid Layers • Imagine that the liquids on the right have the following densities: • 15g/cm3 10g/cm3 • 3g/cm3 9g/cm3 • 7g/cm3 12g/cm3 • Match the colors to the correct densities. 3g/cm3 7g/cm3 9g/cm3 10g/cm3 12g/cm3 15g/cm3
Review • What is the formula for density? • What happens if you pour together liquids that have different densities? • Will the liquid on the top have the highest or lowest density? • Will the liquid on the bottom have the highest or lowest density?
Above your head is a column of air going all the way that column pushes down on everything including you. • Air pressure makes a suction cup work.
The air is densest near sea level and less dense at the top of a mountain • Pressure decreases as altitude decreases
Air pressure affects the boiling of water • Air pressure keeps water in a container, the movement of the molecules tries to. • At sea level, the denser air pushes harder on the water so it has to reach a higher temperature to boil.
…but at the top of a mountain • The air is less dense. • Water boils at a lower temperature. • You must cook food longer.
Diffusion= movement of molecules from high concentration to low • Air moves from areas of high density (pressure) to areas of low density (pressure) • This causes winds
Matter Flashcards • mL = unit of liquid volume • 1.0 g/cm3 = density of fresh water • > 1.0 g/cm3 = sinks in fresh water • < 1.0 g/cm3 = floats in fresh water • 1g = mass of 1 cm3 of fresh water • L x W X H = formula for volume of a rectangular solid • cm3 = unit of solid volume
Solid, Liquid, Gas (a) Particles in solid (b) Particles in liquid (c) Particles in gas
Some Properties of Solids, Liquids, and Gases Property Solid Liquid Gas Shape definite shape takes the shape of takes shape container of container Volume definite volume definite volume expands or shrinks to fill the container Compressible no no yes Arrangement of Fixed, very close Random, close Random, far apart Particles
Plasma, the 4th State of Matter • Energy is so high, atoms vibrate themselves into + and – charged pieces (ions) • Fluorescent lights • Plasma TV’s • The sun • Plasma torches and cutters