Question

use your density skills and the table below to find the identity of the following mystery objects. remember that 1 ml = 1 cm³ and that volume=(lengthwidthheight). another way to find volume is using water displacement. this is when you take your final water volume minus your initial volume to find the volume of your object.

table of densities

solids	density (g/ml)	solids	density (g/ml)
quartz	2.64	gold	19.32
diamond	3.52	platinum	21.4

1. while digging in the backyard, you find an old coin. its mass is 26.76 g and its volume is 3 cm³. what is the coin made of?

1. you think you have found a diamond. its mass is 5.28 g and its volume is 2 cm³. what did you find?

1. you find a ring with a mass of 107 g. to find the volume of the ring, you fill a graduated cylinder with 10ml of water and put the ring into the cylinder. the water rises up to the 15ml mark. what is the ring made of?

1. there is a block on your desk that acts as a paperweight. to find the volume you take 3 measurements. it is a 3cm by 4cm by 6cm block. it has a mass of 184.32 g. what is the block made of?

Explanation:

Step1: Recall density formula

The density formula is $
ho=\frac{m}{V}$, where $
ho$ is density, $m$ is mass and $V$ is volume.

Step2: Solve for question 4

Given $m = 26.76$ g and $V=3$ cm³. Calculate density: $
ho=\frac{26.76}{3}=8.92$ g/cm³. Comparing with the table, it is copper.

Step3: Solve for question 5

Given $m = 5.28$ g and $V = 2$ cm³. Calculate density: $
ho=\frac{5.28}{2}=2.64$ g/cm³. Comparing with the table, it is quartz.

Step4: Solve for question 6

The volume of the ring is found by water - displacement. $V=15 - 10=5$ mL. Given $m = 107$ g. Calculate density: $
ho=\frac{107}{5}=21.4$ g/mL. Comparing with the table, it is platinum.

Step5: Solve for question 7

First, calculate volume $V = 3\times4\times6=72$ cm³. Given $m = 184.32$ g. Calculate density: $
ho=\frac{184.32}{72}=2.56$ g/cm³. Comparing with the table, it is marble.

Answer:

1. Copper
2. Quartz
3. Platinum
4. Marble