Answer:
The balanced molecular equation for the reaction :

Explanation:
The reaction between copper(II) nitrate and potassium carbonate gives solid precipitate of copper(II) carbonate and aqueous solution of potassium nitrate.

According to reaction, 1 mole of copper(II) nitrate reacts with 1 mole of potassium carbonate to give 1 mole of copper(II) carbonate and 2 moles of potassium nitrate,
Radioactivity in our world <span>b. is as old as the universe.
</span><span>Radioactive atom spontaneously emits energetic particles or waves, while decays on lighter nuclei (atoms with smaller atomic mass). Radioactivity is used to calculate how old is Earth and living things, for that purpose isotope of carbon is used.</span>
Answer is: 79.8 grams of copper(II) sulfate.
N(CuSO₄) = 3.01·10²³; number of molecules.
n(CuSO₄) = N(CuSO₄) ÷ Na.
n(CuSO₄) = 3.01·10²³ ÷ 6.02·10²³ 1/mol.
n(CuSO₄) = 0.5 mol; amount of substance.
m(CuSO₄) = n(CuSO₄) · M(CuSO₄).
m(CuSO₄) = 0.5 mol · 159.6 g/mol.
m(CuSO₄) = 79.8 g; mass of substance.
M - molar mass.