Answer:
(c) only Ca2+(aq) and Hg2+(aq)
Explanation:
- In the first step, hydrochloric acid (HCl) is added to the solution. In this case the equilibrium that could take place is:
Ag⁺(aq) + Cl⁻(aq) ↔ AgCl(s)
But no precipitate was formed, so Ag⁺(aq) is absent.
- By adding H₂SO₄(aq) the next equilibrium that could take place is:
Ca⁺²(aq) + SO₄⁻²(aq) ↔ CaSO₄(s)
A white precipitate was formed, so Ca⁺² is present in the solution.
- The following could take place after adding H₂S(aq):
Hg²⁺(aq) + S⁻² ↔ HgS(s)
A black precipitate formed, so Hg⁺² is present as well.
Answer : The balanced molecular equation will be:

Explanation :
Molecular equation : It is a balanced chemical reaction in which the ionic compounds are expressed as the molecules instead of component ions.
According to the question, when iron react with copper (II) sulfate then it react to give iron (II) sulfate and copper as a product. In this reaction, iron is more reactive metal than the copper metal. So, it can easily displace copper metal form the solution.
The balanced molecular equation will be:

Answer:
Low energy waves have <u>a long wavelength.</u>
Explanation:
Energy of wave is directly related to the frequency while it is inversely proportional to the wavelength.
If any wave have high energy it will have high frequency and smaller wavelength.
If the wave have lower energy then it will have lower frequency and higher wavelength.
Mathematical relationship:
E = h. f
E = h. c/λ
E= energy
h = planck's constant
f = frequency
c = speed of light
λ = wavelength
If you start with 40.0 grams of the element at noon, 10.0 grams
radioactive element will be left at 2 p.m. The correct answer between
all the choices given is the second choice or letter B. I am hoping that this
answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.