Because when you take the sand out it doesn't stay the same shape
Answer:
Density, melting point. and magnetic properties
Explanation:
I can think of three ways.
1. Density
The density of Cu₂S is 5.6 g/cm³; that of CuS is 4.76 g/cm³.
It should be possible to distinguish these even with high school equipment.
2. Melting point
Cu₂S melts at 1130 °C (yellowish-red); CuS decomposes at 500 °C (faint red).
A Bunsen burner can easily reach these temperatures.
3. Magnetic properties
You can use a Gouy balance to measure the magnetic susceptibilities.
In Cu₂S the Cu⁺ ion has a d¹⁰ electron configuration, so all the electrons are paired and the solid is diamagnetic.
In CuS the Cu²⁺ ion has a d⁹ electron configuration, so all there is an unpaired electron and the solid is paramagnetic.
A sample of Cu₂S will be repelled by the magnetic field and show a decrease in weight.
A sample of CuS will be attracted by the magnetic field and show an increase in weight.
In the picture below, you can see the sample partially suspended between the poles of an electromagnet.
Answer:
Sand
Explanation:
with salt distillation will work, heat the solution and collect the water in a seperate beaker
With sugar you do the same, boil away the water and collect the water vapour, you'll be left with sugar in the original container and water if you collected it
Use a fraction of column and heat the solution, the alcohol will be seperated out
Sand is the only one that uses mechanical filtration
Answer:
wax, candlewick, and oxygen
Explanation:
The burning of the candle is both a physical as well as a chemical change. The reactants are the substances or the raw materials that are required for a reaction to the process. In the process of burning a candle, the reactants are the fuel which includes wax and wick, and oxygen which is found in the air. The products found at the end of the reaction are carbon dioxide and water vapor.
Answer:
a molecule with two of the same element
Explanation: