Question

1. fill in the following table.

name | symbol | z | a | #p | #e | #n | isotopic symbol
sodium | na | 11 | 23 | 11 | 11 | 12 |
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
phosphorus | p | 15 | 31 | 15 | 15 | 16 |
iron | fe | 26 | 56 | 26 | 26 | 30 |
iodine | i | 53 | 127 | 53 | 53 | 74 |

Explanation:

Problem 7:

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

Sodium:

• \( Z = 11 \), \( A = 23 \), Symbol = Na
• Isotopic Symbol: $\ce{^{23}_{11}Na}$

Chlorine:

• \( Z = 17 \), \( A = 35 \), Symbol = Cl
• Isotopic Symbol: $\ce{^{35}_{17}Cl}$

Potassium:

• \( Z = 19 \), \( A = 39 \), Symbol = K
• Isotopic Symbol: $\ce{^{39}_{19}K}$

Problem 8:

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

Phosphorus:

• \( Z = 15 \), \( A = 31 \), Symbol = P
• Isotopic Symbol: $\ce{^{31}_{15}P}$

Iron:

• \( Z = 26 \), \( A = 56 \), Symbol = Fe
• Isotopic Symbol: $\ce{^{56}_{26}Fe}$

Iodine:

• \( Z = 53 \), \( A = 127 \), Symbol = I
• Isotopic Symbol: $\ce{^{127}_{53}I}$

Filled Tables:

Table for Problem 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 for Problem 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	$\ce{^{127}_{53}I}$

Answer:

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

Phosphorus:

• \( Z = 15 \), \( A = 31 \), Symbol = P
• Isotopic Symbol: $\ce{^{31}_{15}P}$

Iron:

• \( Z = 26 \), \( A = 56 \), Symbol = Fe
• Isotopic Symbol: $\ce{^{56}_{26}Fe}$

Iodine:

• \( Z = 53 \), \( A = 127 \), Symbol = I
• Isotopic Symbol: $\ce{^{127}_{53}I}$

Filled Tables:

Table for Problem 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 for Problem 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	$\ce{^{127}_{53}I}$