Answer:
The pitch of the sound a person makes is determined by several factors, including the size and tension of his or her vocal cords.
Explanation:
C) Noble gases
The six noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Their atomic numbers are, respectively, 2, 10, 18, 36, 54, and 86.
<span>Na2CO3 (aq) + CaCl2H4O2 (aq) = CaCO3 (s) + 2 NaCl (aq) + 2 H2O (l)</span>
Answer:
The answer to your question is CuSO₄
Explanation:
To answer your question just remember the following information
- A chemical reaction is divided into sections
reactants and products
reactants on the left side of the reaction
products on the right side of the reaction
- All the symbols have a meaning
(s) means that that compound is in solid phase
(aq) means that that compound is dissolved in solution.
Then, the answer is CuSO₄
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.