Question

13
what are the numbers of protons, neutrons, and electrons in the ion $_{92}^{238}x^{+2}$?
146 protons, 92 neutrons, 144 electrons
92 protons, 238 neutrons, 90 electrons
92 protons, 146 neutrons, 94 electrons
92 protons, 146 neutrons, 90 electrons
14
how many electrons does the ion $_{15}^{31}p^{-3}$ contain?

Explanation:

Question 13

Step1: Determine number of protons

The atomic number (bottom number) is 92, so protons = 92.

Step2: Calculate number of neutrons

Mass number (top number) is 238. Neutrons = mass number - atomic number = \( 238 - 92 = 146 \).

Step3: Find number of electrons

The ion is \( X^{+2} \), meaning it lost 2 electrons. Neutral atom has electrons = protons = 92. So electrons = \( 92 - 2 = 90 \).

Step1: Determine protons from atomic number

Atomic number of P is 15, so protons = 15 (neutral atom has electrons = protons = 15).

Step2: Calculate electrons in \( P^{-3} \)

The ion has a -3 charge, meaning it gained 3 electrons. So electrons = \( 15 + 3 = 18 \).

Answer:

92 protons, 146 neutrons, 90 electrons (the last option with this combination)

Question 14