Notes Science Essential Question(s) What is density? What is mass? What is volume? How do I calculate density? How do I multiply and divide with decimals? Tennessee SPI Objective: Apply an equation to determine the density of an object based on its mass and volume Check for Understanding Calculate the density of various objects. SPI Density Instructions 1) First click on "View" from the top-menu bar. 2) Then click on "Slide Show" from the drop-down menu. 3) Then use the right-arrow button on your keyboard to advance through this presentation.

Silly Thought 20 Never trust an atom. They make up everything. Humor

SPI Density What is density?  Density is the amount of matter (mass) you have crammed in a given space (volume) Reminder: mass is how much matter is in an object  The unit for mass is grams (mg or g or kg) Reminder: volume is how much space it takes up (size)  Unit for solid volume is cubic meters (cm 3 or m 3 or km 3 )  Unit for liquid volume is liters (mL or L or kL) To compute density  - divide the mass by the volume of the object Science Notes Demonstration: Demonstrate with wadded up paper in a trash can

Density Example:  Here are two objects that are the same size. (1) Bowling Ball and (2) Soccer Ball  One of these objects contains more matter (bowling ball).  With two same-sized objects like this, the object with more mass has greater density than the other object. More Dense Less Dense SPI Density Science Notes

Use this formula: Density=mass divided by volume Quick Practice SPI Density Science Solve The Three Density Problems Shown Below Go ahead and use a calculator (for now) Density= volume mass 1) …density of an object with a mass of 25g a volume of 10cm 3 ? Example: 25 (mass) divided by 10 (volume) 2) …density of an object with a mass of 45kg a volume of 43m 3 ? Example: 45 (mass) divided by 43 (volume) 3) …density of an object with a mass of 350g a volume of 95cm 3 ? Example: 350 (mass) divided by 95 (volume) Density= Density= Density= D= M /V or MVMV D= Units… g/cm 3 Units… kg/cm 3 Units… g/cm 3

Answers 1) …density of an object with a mass of 25g & volume of 10cm 3 ? 25g ÷ 10cm 3 = 2.5g/cm 3 2) …density of an object with a mass of 45kg & volume of 43m 3 ? (round up to the nearest hundredth) 45kg ÷ 43m 3 = 1.05kg/m 3 3) …density of an object with a mass of 350g & volume of 95cm 3 ? (round up to the nearest hundredth) 350g ÷ 95cm 3 = 3.68g/cm 3 SPI Density Science Notes Density=mass divided by volume Don't Forget Your Units! Example: grams/centimeter cubed Written like this… g/cm 3

SPI Density What is density?  Density is the amount of matter (mass) you have crammed in a given space (volume) Density can be… Low, Moderate, or High Low: Cotton Candy Moderate: A brick High: A diamond Science Notes Demonstration Demonstration in restroom foyer….lets go!

1) Identify which liquids would occupy levels A, B, and C according to their density. Level C Level B Level A DesignationSubstanceDensity Liquid 01Water1.0 g/mL Liquid 02Liquid Mercury13.6 g/mL Liquid 03Turpentine0.8 g/mL Turpentine (0.8 g/mL) Water (1.0 g/mL) Mercury (13.6 g/mL) SPI (Density) ANSWERS Science Notes SPI Density Density In Liquids Lower density liquids will float on top of liquids with higher density Example: Oil floats on top of water

SPI Density Science Notes Density In Liquids  Lower density liquids float on top of liquids with higher density  Higher density liquids will sink below lower density liquids View this YouTube Video Clip: Link: 7-Layer Density Column7-Layer Density Column

Mass: 12g Volume: 3cm 3 Mass: 23g Volume: 5cm 3 Mass: 11g Volume: 3cm 3 Mass: 19g Volume: 7cm 3 (A) (D) (C) (B) 4 g/cm g/cm g/cm g/cm 3 Science Notes SPI Density Which cube above has the GREATEST density? Find the density if each of these objects Again…go ahead and use a calculator (for now)

Mass: 18g Volume: 6cm 3 Mass: 21g Volume: 5cm 3 Mass: 30g Volume: 8cm 3 Mass: 29g Volume: 7cm 3 (A) (D) (C) (B) 3 g/cm g/cm g/cm g/cm 3 Science Notes SPI Density Find the density if each of these objects Again…go ahead and use a calculator (for now) Which cube above has the LEAST density?