Question

1. use your density skills to find the identity of the following mystery objects:

table of densities
solid density g/cm³ solid density g/cm³
marble 2.58 copper 8.92
quartz 2.64 gold 19.32
diamond 3.52 platinum 21.4
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?
you think you have found a diamond. its mass is 5.28 g and its volume is 2 cm³.
what did you find?
you find a ring with a mass of 107 g. you fill a graduated cylinder up with 10 ml of water and put the ring into the cylinder. the water rises up to the 15 ml mark.
what is the ring made of?
there is a block on your desk that acts as a paperweight. its measurements are 3 cm by 4 cm by 6 cm. the block has a mass of 184.32 g.
what is the block made of?
challenge question

Explanation:

Step1: Calculate density of coin

$
ho_{coin}=\frac{m_{coin}}{V_{coin}}=\frac{26.76\ g}{3\ cm^{3}} = 8.92\ g/cm^{3}$

Step2: Calculate density of diamond - like object

$
ho_{diamond - like}=\frac{m}{V}=\frac{5.28\ g}{2\ cm^{3}} = 2.64\ g/cm^{3}$

Step3: Calculate density of ring

$V_{ring}=15\ mL - 10\ mL = 5\ mL = 5\ cm^{3}$, $
ho_{ring}=\frac{m_{ring}}{V_{ring}}=\frac{107\ g}{5\ cm^{3}} = 21.4\ g/cm^{3}$

Step4: Calculate density of block

$V_{block}=3\ cm\times4\ cm\times6\ cm = 72\ cm^{3}$, $
ho_{block}=\frac{m_{block}}{V_{block}}=\frac{184.32\ g}{72\ cm^{3}} = 2.56\ g/cm^{3}$

Step5: Identify materials

Match densities with table.

Answer:

Coin: Copper
Diamond - like object: Quartz
Ring: Platinum
Block: Marble