Questions: Use the following to answer questions 12-17: Determine the number of protons and the number of neutrons for each of the following. 12. Rb-85 37 R Rb 85-37=48 n 13. Sn-118 14. C-14 15. I-127 16. Pb-207 17. Hg-201

Use the following to answer questions 12-17:
Determine the number of protons and the number of neutrons for each of the following.
12. Rb-85 37 R Rb 85-37=48 n
13. Sn-118
14. C-14
15. I-127
16. Pb-207
17. Hg-201

Transcript text: Use the following to answer questions 12-17: Determine the number of protons and the number of neutrons for each of the following. 12. $\mathrm{Rb}-85$ ${ }_{37}{ }^{R} \mathrm{Rb}$ $85-37=48 n$ 13. $\mathrm{Sn}-118$ 14. C-14 15. I-127 16. $\mathrm{Pb}-207$ 17. $\mathrm{Hg}-201$

Solution

Solution Steps

Step 1: Understanding the Notation

The notation for an element, such as $\mathrm{Rb}-85$, indicates the element and its mass number. The mass number is the sum of protons and neutrons in the nucleus.

Step 2: Determine the Number of Protons

The number of protons in an element is given by its atomic number. This can be found on the periodic table. For example, for $\mathrm{Rb}$ (Rubidium), the atomic number is 37, which means it has 37 protons.

Step 3: Determine the Number of Neutrons

The number of neutrons is calculated by subtracting the atomic number from the mass number. For $\mathrm{Rb}-85$, the calculation is: \[ 85 - 37 = 48 \] So, $\mathrm{Rb}-85$ has 48 neutrons.