Question

1. what is the mass number of an atom that contains 23 protons, 23 electrons, and 28 neutrons? (3pts)

□ 5
□ 28
□ 51
□ 74

1. how many electrons are in the neutral atom of cr-52? (3pts)

□ 24
□ 28
□ 52
□ 26

Explanation:

Step1: Calculate mass number

$\text{Mass number} = \text{Protons} + \text{Neutrons} = 23 + 28 = 51$

Step2: Find electrons in neutral Cr-52

In neutral atoms, $\text{Electrons} = \text{Atomic number of Cr}$. Chromium (Cr) has an atomic number of 24, so electrons = 24.

Answer:

1. D. 51
2. A. 24