Question

1. determine the number of protons, neutrons and electrons in the following: (4 pts)

tellurium
52
127.60
p+
no
p+
no
k
19
39.098

Explanation:

Step1: Recall atomic - number and mass - number rules

The atomic number ($Z$) is equal to the number of protons and the number of electrons in a neutral atom. The mass number ($A$) is the sum of protons and neutrons. For potassium ($K$), the atomic number is 19 and the average atomic mass is approximately 39.0983. For tellurium ($Te$), the atomic number is 52 and the average atomic mass is approximately 127.60.

Step2: Determine protons, neutrons and electrons for potassium

For potassium ($K$):

• The number of protons ($p^+$) is equal to the atomic number. So, $p^+ = 19$.
• In a neutral atom, the number of electrons ($e^-$) is equal to the number of protons. So, $e^-=19$.
• The number of neutrons ($n^0$) is calculated as $n^0=A - Z$. Taking the average atomic mass as approximately 39, $n^0 = 39 - 19=20$.

Step3: Determine protons, neutrons and electrons for tellurium

For tellurium ($Te$):

• The number of protons ($p^+$) is equal to the atomic number. So, $p^+ = 52$.
• In a neutral atom, the number of electrons ($e^-$) is equal to the number of protons. So, $e^- = 52$.
• The number of neutrons ($n^0$) is calculated as $n^0=A - Z$. Taking the average atomic mass as 127.60, and rounding the mass - number to 128, $n^0=128 - 52 = 76$.

Answer:

For potassium ($K$): $p^+=19$, $n^0 = 20$, $e^-=19$
For tellurium ($Te$): $p^+=52$, $n^0 = 76$, $e^-=52$