Answer:
The necklace is fake.
The necklace is made up of copper.
Explanation:
The following data were obtained from the question:
Mass of the necklace = 21.3 g
Volume of water = 5 mL
Volume of water + Necklace = 7.4 mL
To identify the composition of the necklace, we shall determine the density of the necklace.
This can be obtained as follow:
We'll begin by calculating the volume of the necklace. This can be obtained as shown below:
Volume of water = 5 mL
Volume of water + Necklace = 7.4 mL
Volume of Necklace =.?
Volume of Necklace = (Volume of water + Necklace) – (Volume of water)
Volume of Necklace = 7.4 – 5
Volume of Necklace = 2.4 mL
NOTE:
1 mL = 1 cm³
Therefore,
Volume of Necklace = 2.4 mL = 2.4 cm³
Finally, we shall determine the density of the necklace as follow:
Mass of the Necklace = 21.3 g
Volume of Necklace = 2.4 cm³
Density of Necklace =?
Density = mass /volume
Density = 21.3 / 2.4
Density = 8.87 g/cm³
Therefore, the density of the necklace is 8.87 g/cm³.
From the question given above, we were told Jacy bought a gold necklace.
But comparing the density of necklace to the densities given above the necklace is obviously made of copper material.
Therefore, Jacy bought a fake gold necklace.