Name: ANSWER KEY Pd: Date: Individually work on this self-assessment your understanding density. Part I: Answer the questions below. SOLID Density Review Block E A B C D E H = 3.00 F G H I J K L M N O L = 5.00 W = H = E L = W = 1. Density is a measurement the amount Mass per unit. olume 2. Calculate the Density the SOLID OBJECT above. Assume that its mass is 8.53g. Show your work below: (a) What Formula are you using: = L x W x H (b) What Numbers and Labels are you using in this formula: = 5.00 x x 3.00 (c) What is the Answer: = 15.00 3 D = 8.53g 15.00 3 D = 0.569 g/ 3 3. What is the MASS Block E pictured above, assuming it was pulled out the SOLID OBJECT above? Mass = 0.569 g 4. How did you get the answer you did for question number 3? Explain how you found the answer. The Density the Large is 0.569 g/ 3. This means that every one unit volume has this mass. Since Block E is a single unit volume, it has to have a mass equal to the density the object.
5.) What would the density a liquid need to be in order to have ALL the following objects float in it? 1.745 g/ 3 4.510 g/ 3 0.389 g/ 3 19.575 g/ 3 In order to have all these objects float, they would need to be placed in a liquid that has a density 19.576 g/ml or larger. 6.) Why does a Hot Air Balloon rise up? Hot air is less dense than cold air. When the balloon operator wants the balloon to rise he/she pulls on a cord which increase the size a flame at the base the balloon. This larger flame increases the temperature the air in the balloon making it less dense than the air outside the balloon 7.) What s the Density Water? Pure water has a density 0 g/ml 8.) Explain the following pictures in terms Density. When you tip the milk jug sideways, the milk will Sink through the Air and find its way to the bottom the glass because it is denser than the air. When you tip the Chocolate sideways, the syrup will Sink through the milk and find its way to the bottom the glass because it is denser than the milk.
Part II: Below are examples from the density labs you have completed in class. Look them over and FIRST make any corrections that might need to be made, and then SECOND -explain why you made the corrections. [CUBE OBJECT] LENGTH WIDTH HEIGHT MASS OLUME OBJECT DENSITY G 15.57 4.5 0.85 59.56 120.33 g 0.495 ml/g (A) (B) (C) (D) (E) Here) 15.57 4.50 59.56 3 2.020 g/ 3 (A) No Label (B) No Best Guess Number (C) Wrong Label (D) Density is M not M There are 5 corrections (E) Wrong Label [CYLINDER OBJECT] OBJECT Diameter Radius HEIGHT OLUME MASS DENSITY #4 6.89 3.45 2.1 49.92 3 67 g 0.854 g/ml Here) (A) 2.10 (C) 78.49 3 (D) 67.00 g There are 5 corrections (A) No Best Guess Number (B) No Label (C) olume Cylinders = π x r 2 x H (D) Not the Correct Number Decimals (Plus no Best Guess) (E) Wrong Label (B) (E) 0.854 g/ 3
[IRREGULARLY SHAPED OBJECT Direct Displacement (see above diagram)] Before is Added 30 OBJECT olume H 2 O After olume H 2 O Before OLUME MASS DENSITY Solid Rock Here) 27.60 20.55 ml 6.7 ml 3 13.9900 1.970 g/ml 3 (A) (B) (C) 26.6 ml (D) 20.5 ml (E) (F) 6.1 3 (G) (H) 13.99 g (I) (J) 2.293 g/ 3 20 After is Added There are 10 corrections (A) Wrong Measurement from Graduated Cylinder (B) Too many decimals (More than Best Guess) (C) Wrong Label (D) Too many decimals (More than Best Guess) (E) olume = H 2 O After H 2 O Before (F) Wrong Label (G) Too many decimals (More than Best Guess) (H) No Label (I) Density is M (J) Wrong Label 30 20 [IRREGULARLY SHAPED OBJECT Overflow Displacement] olume MASS DENSITY OBJECT H 2 O Displaced Gold Bar 38 734.6 g 0.052 g/ (A) (B) (C) (D) (E) Here) 38.0 ml 734.60 g 19.332 g/ 3 There are 5 corrections (A) No Best Guess Number (B) Wrong Label (C) No Best Guess Number (D) Density is M not M (E) Wrong Label
[LIQUID OBJECT] Liquid olume Liquid Mass Graduated Cylinder and Liquid Mass Empty Graduated Cylinder MASS Liquid DENSITY Yellow 11.3 34.7 g 25.06 ml 9.64 g 0.853 g/ 3 (A) (B) (C) (D) Here) 11.3 ml 34. 70 g 25.06 g 0.853 g/ml There are 4 corrections (A) No Label (B) No Best Guess Number (C) Wrong Label (D) Wrong Label Part III: Identify what material each the following Unknown objects below is made from by first finding the density the Known objects on the next and then comparing them to densities the Unknown objects. UNKNOWN s UNKNOWN A olume = 16.79 3 Mass = 131.90 g UNKNOWN B olume = 34.00 3 Mass = 248.20 g UNKNOWN C olume = 7.11 3 Mass = 135.59 g UNKNOWN D olume = 11.05 3 Mass = 10.72 g This is made This is made This is made This is made IRON TIN Uranium Sodium D = 131.90 g 16.79 3 D = 248.20 g 34.00 3 D = 135.59 g 7.11 3 D = 10.72 g 11.05 3 D = 7.856 g/ 3 D = 7.300 g/ 3 D = 19.070 g/ 3 D = 0.970 g/ 3
KNOWN OBJECTS On a separate piece paper, calculate the densities each the follow Known objects. Make sure you show all your work and attach the paper behind this page. GOLD Cube L = 3.12 W = 1.34 H = 2.00 Mass = 161.35 g IRON Cylinder Diameter = 0.50 H = 5.67 Mass = 8.72 g COPPER Cube L = 7.89 W = 1.94 H = 1.94 Mass = 117.57 g SODIUM Cylinder Diameter = 4.62 H = 3.75 Mass = 60.95 g Density Density Density Density = L x W x H = 3.12 x 1.34 x 2.00 = 8.36 3 = π x r 2 x H = 3.14 x (0.25) 2 x 5.67 = 1.11 3 = L x W x H = 7.89 x 1.94 x 1.94 = 29.69 3 = π x r 2 x H = 3.14 x (2.31) 2 x 3.75 = 62.83 3 D = 161.35 g 8.36 3 D = 8.72 g 1.11 3 D = 117.57 g 29.69 3 D = 60.95 g 62.83 3 D = 19.300 g/ 3 D = 7.856 g/ 3 D = 3.960 g/ 3 D = 0.970 g/ 3 Tin Cube L = 1.21 W = 5.89 H = 8.67 Mass = 451.07 g Zinc Cylinder Diameter = 3.15 H = 12.48 Mass = 694.08 g Nickel Cube L = 6.41 W = 6.41 H = 6.41 Mass = 2343.99 g Uranium Cylinder Diameter = 2.54 H = 0.85 Mass = 82.00 g Density Density Density Density = L x W x H = 1.21 x 5.89 x 8.67 = 61.79 3 = π x r 2 x H = 3.14 x (1.58) 2 x 12.48 = 97.83 3 = L x W x H = 6.41 x 6.41 x 6.41 = 263.37 3 = π x r 2 x H = 3.14 x (1.27) 2 x 0.85 = 4.30 3 D = 451.07 g 61.79 3 D = 694.08 g 97.83 3 D = 2343.99 g 263.37 3 D = 82.00 g 4.30 3 D = 7.300 g/ 3 D = 7.095 g/ 3 D = 8.900 g/ 3 D = 19.070 g/ 3