B. A solar cycle usually lasts 11 years.
Explanation:
Monitor the temperature of the water with the thermometer. Stop heating the water once it nears the boiling point of 100 degrees Celsius. Add copper(II) sulfate and stir until the heated solution is saturated. When the solution is saturated, copper(II) sulfate will not dissolve anymore
The atomic number is always equal to the number of protons. It will be equal to the number of elections also if the atom has a neutral charge.
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