Matter and Measurement - Last week we learned about metric measurements. But what will we measure? How about matter? - Matter is EVERYTHING around you! The table, your chair, pens, paper – everything. -Matter can exist in many different states, including as a solid, liquid, gas, or plasma. - All matter has mass and volume, which both work together to determine matter’s density.

-Matter can exist in many different states, including as a solid, liquid, gas, or plasma. What Holds Matter Together? - The low-energy molecules in a solid are tightly packed together. They don’t move very easily. If you add heat or pressure, you can make a liquid. - The medium-energy molecules in a liquid like to glide around, sliding against each other. They move in a flow. Adding heat will turn this into a gas; freezing makes a solid. - The high-energy molecules in a gas barely know each other. They move around like hyperactive bees. Adding pressure or decreasing temperature can create a liquid.

How Does Matter Change? - You must either add heat to a substance or remove heat from it if you want to change its state (also called phase). Changes in State/Phase: - liquid to gas - vaporization, by process of evaporation - solid to gas - sublimation - liquid to solid - freezing - solid to liquid - melting - gas to liquid - condensation - gas to solid - deposition

Physical vs. Chemical Change Physical change will change the visible appearance, without changing the composition of the material. –Boil, melt, cut, bend, split, crack –Is boiled water still water? –Can be reversible, or irreversible Chemical change - a change where a new form of matter is formed. –Rust, burn, decompose, ferment

States of Matter Cheat Sheet Solid Liquid Gas Definite Volume? YES NO Definite Shape? YES NO Result of a Temperature Increase? Small Expansion Will it Compress? NO YES Small Expansion Large Expansion

4 th state: - formed at high temperatures; ionized phase of matter as found in the sun 4 th state: Plasma - formed at high temperatures; ionized phase of matter as found in the sun

Mass is the amount of material in an object (NOT the same as weight!!) -Mass stays the same no matter what force is acting on the object. -This makes mass different from weight, which depends on both the amount of mass and the amount of gravity (measured on a scale). How to Measure Matter

Volume is the amount of space taken up or occupied by an object. - Depending on the state (solid, liquid, gas, or plasma), volume can be measured in many ways. SOLID m 3 LIQUID L or mL GAS L or mL PLASMA L or mL L x W x H How to Measure Matter

Density = g 22.7 cm 3 Density = Mass (g) Volume (cm 3) Density is a measurement of how tightly packed matter is within a certain object. - Density is calculated by dividing mass by volume. A student finds a rock on the way to school. In the lab he determines that the volume of the rock is 22.7 cm 3, and the mass in g. What is the density of the rock? Density = g/cm 3 How to Measure Matter

Mass is the amount of matter in an object or substance. Volume is the amount of space an object or substance takes up. Density is the amount of matter in a certain unit of volume or space, and it is the measure of how tightly packed molecules are within a substance. - Substances of greater density will sink below those of lesser density. - NOT the same as weight, which changes according to gravity. Recap of Measurement