Questions: Question 25 In the calcium atom represented by the symbol Ca, there are 20 protons, 20 neutrons, and 20 electrons. True False

Solution Steps

The symbol for the calcium atom is given as \({}_{20}^{10} \mathrm{Ca}\). This notation provides two key pieces of information:

• The atomic number (Z) is 20, which is the number of protons.
• The mass number (A) is 10, which is the sum of protons and neutrons.

From the atomic number (Z = 20), we know:

• The number of protons is 20.

The mass number (A = 10) is the sum of protons and neutrons: \[ A = Z + N \] \[ 10 = 20 + N \] \[ N = 10 - 20 \] \[ N = -10 \]

This result is not physically possible, indicating an error in the given symbol. The mass number should be greater than or equal to the atomic number.

Given the inconsistency in the provided symbol, the statement that there are 20 protons, 20 neutrons, and 20 electrons in the calcium atom represented by \({}_{20}^{10} \mathrm{Ca}\) is false.

Final Answer