Question

1. the numbers of protons, neutrons, and electrons in $_{19}^{39}k^{+}$ are: 20 p, 19 n, 19 e; 19 p, 20 n, 20 e; 19 p, 20 n, 18 e; 19 p, 20 n, 19 e

Explanation:

Step1: Identify proton number

The atomic number of potassium (K) is 19. For any atom or ion, the number of protons is equal to the atomic number. So, the number of protons (p) in \(^{39}_{19}K^{+}\) is 19.

Step2: Calculate neutron number

The mass - number (A) is 39. The formula for calculating the number of neutrons (n) is \(n=A - Z\), where Z is the atomic number. So, \(n = 39-19=20\).

Step3: Determine electron number

A neutral potassium atom has 19 electrons (equal to the number of protons). The \(K^{+}\) ion has a + 1 charge, which means it has lost 1 electron. So the number of electrons (e) is \(19 - 1=18\).

Answer:

19 p, 20 n, 18 e