Question

1. fill in the following table.

name	symbol	z	a	#p	#e	#n	isotopic symbol
chlorine	cl	17	35	17	17	18
potassium	k	19	39	19	19	20

1. fill in the following table.

name	symbol	z	a	#p	#e	#n	isotopic symbol
iron	fe	26		26	26
iodine	i	53		53	53

Explanation:

Problem 7

Step 1: Recall Isotopic Symbol Format

The isotopic symbol is written as $\ce{^{A}_{Z}X}$, where \( X \) is the symbol, \( Z \) is atomic number, \( A \) is mass number.

Step 2: Sodium

For Sodium (\( \text{Na} \)), \( Z = 11 \), \( A = 23 \). Isotopic symbol: $\ce{^{23}_{11}Na}$

Step 3: Chlorine

For Chlorine (\( \text{Cl} \)), \( Z = 17 \), \( A = 35 \). Isotopic symbol: $\ce{^{35}_{17}Cl}$

Step 4: Potassium

For Potassium (\( \text{K} \)), \( Z = 19 \), \( A = 39 \). Isotopic symbol: $\ce{^{39}_{19}K}$

Problem 8

Step 1: Recall Relationships

• Atomic number (\( Z \)) = number of protons (\( \#p \)) = number of electrons (\( \#e \)) (for neutral atoms)
• Mass number (\( A \)) = \( \#p + \#n \)
• Isotopic symbol: $\ce{^{A}_{Z}X}$

Step 2: Phosphorus

• \( Z = 15 \), \( \#p = 15 \), \( \#e = 15 \)
• Assume common isotope: \( A = 31 \) (since \( \#n = A - Z \), common \( \#n = 16 \), so \( A = 15 + 16 = 31 \))
• Isotopic symbol: $\ce{^{31}_{15}P}$

Step 3: Iron

• \( Z = 26 \), \( \#p = 26 \), \( \#e = 26 \)
• Common isotope: \( A = 56 \) ( \( \#n = 56 - 26 = 30 \))
• Isotopic symbol: $\ce{^{56}_{26}Fe}$

Step 4: Iodine

• \( Z = 53 \), \( \#p = 53 \), \( \#e = 53 \)
• Common isotope: \( A = 127 \) ( \( \#n = 127 - 53 = 74 \))
• Isotopic symbol: $\ce{^{127}_{53}I}$

Filled Tables

Table 7:

Name	Symbol	\( Z \)	\( A \)	\( \#p \)	\( \#e \)	\( \#n \)	Isotopic Symbol
Chlorine	Cl	17	35	17	17	18	$\ce{^{35}_{17}Cl}$
Potassium	K	19	39	19	19	20	$\ce{^{39}_{19}K}$

Table 8:

Name	Symbol	\( Z \)	\( A \)	\( \#p \)	\( \#e \)	\( \#n \)	Isotopic Symbol
Iron	Fe	26	56	26	26	30	$\ce{^{56}_{26}Fe}$
Iodine	I	53	127	53	53	74	$\ce{^{127}_{53}I}$

(Note: For \( \#n \) in Table 8, calculated as \( A - Z \):

• Phosphorus: \( 31 - 15 = 16 \)
• Iron: \( 56 - 26 = 30 \)
• Iodine: \( 127 - 53 = 74 \))

Answer:

Step 1: Recall Relationships

• Atomic number (\( Z \)) = number of protons (\( \#p \)) = number of electrons (\( \#e \)) (for neutral atoms)
• Mass number (\( A \)) = \( \#p + \#n \)
• Isotopic symbol: $\ce{^{A}_{Z}X}$

Step 2: Phosphorus

• \( Z = 15 \), \( \#p = 15 \), \( \#e = 15 \)
• Assume common isotope: \( A = 31 \) (since \( \#n = A - Z \), common \( \#n = 16 \), so \( A = 15 + 16 = 31 \))
• Isotopic symbol: $\ce{^{31}_{15}P}$

Step 3: Iron

• \( Z = 26 \), \( \#p = 26 \), \( \#e = 26 \)
• Common isotope: \( A = 56 \) ( \( \#n = 56 - 26 = 30 \))
• Isotopic symbol: $\ce{^{56}_{26}Fe}$

Step 4: Iodine

• \( Z = 53 \), \( \#p = 53 \), \( \#e = 53 \)
• Common isotope: \( A = 127 \) ( \( \#n = 127 - 53 = 74 \))
• Isotopic symbol: $\ce{^{127}_{53}I}$

Filled Tables

Table 7:

Name	Symbol	\( Z \)	\( A \)	\( \#p \)	\( \#e \)	\( \#n \)	Isotopic Symbol
Chlorine	Cl	17	35	17	17	18	$\ce{^{35}_{17}Cl}$
Potassium	K	19	39	19	19	20	$\ce{^{39}_{19}K}$

Table 8:

Name	Symbol	\( Z \)	\( A \)	\( \#p \)	\( \#e \)	\( \#n \)	Isotopic Symbol
Iron	Fe	26	56	26	26	30	$\ce{^{56}_{26}Fe}$
Iodine	I	53	127	53	53	74	$\ce{^{127}_{53}I}$

(Note: For \( \#n \) in Table 8, calculated as \( A - Z \):

• Phosphorus: \( 31 - 15 = 16 \)
• Iron: \( 56 - 26 = 30 \)
• Iodine: \( 127 - 53 = 74 \))