Answer:
Beryllium, because it is in period 2 and has four total electrons.
Explanation:
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The equivalence is point in a titration is the point at which you have neutralized all of your base/acid with your titrant acid/base from a buret. This can be seen with indicators which change color at the equivalence point in a titration to signal to you that all of your base/acid has been reacted with. For example, all your molecules of OH⁻ from a NaOH base in a beaker have been neutralized by H⁺of HCl acid from your titrant in a buret leaving only Na⁺ ions and Cl⁻ ions and neutral H₂O molecules.
When solutions of sodium sulfide and copper(ii) sulfate are mixed, a precipitate of copper(ii) sulfide is formed. The net ionic equation for this reaction is Cu⁺² (aq) + S⁻² (aq) → CuS (s).
<h3>What is Balanced Chemical Equation ?</h3>
The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.
Now first write the balanced chemical equation
CuSO₄ (aq) + Na₂S (aq) → CuS(s) + Na₂SO₄ (aq)
Now write the net ionic equation
Cu⁺² (aq) + SO₄⁻² (aq) + 2Na⁺ (aq) + S⁻² (aq) → CuS (s) + 2Na⁺ + SO₄⁻² (aq)
So the net ionic equation is
Cu⁺² (aq) + S⁻² (aq) → CuS (s)
Thus from the above conclusion we can say that When solutions of sodium sulfide and copper(ii) sulfate are mixed, a precipitate of copper(ii) sulfide is formed. The net ionic equation for this reaction is Cu⁺² (aq) + S⁻² (aq) → CuS (s).
Learn more about the Balanced Chemical Equation here: brainly.com/question/26694427
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Answer:
Observation affects the outcome