Question

1. complete the following table:

isotope name	isotope notation	atomic number	mass number	# protons	# electrons	# neutrons
			16	8
	<sup>60</sup><sub>28</sub>ni
			25		28
			24		11

1. even when something is always found in nature as a whole number, its average may not work out to be a whole number. what is the average number of pets for your class?
2. the average atomic mass of chlorine is 35.45 u. is it possible for any single atom of chlorine to have a mass number of 35.45 u? explain.
3. the average atomic mass of potassium is 39.1 u. potassium exists as three isotopes: potassium - 39, potassium - 40, and potassium - 41. which isotope do you think is found most commonly in nature? explain your answer.

Explanation:

Step1: Recall atomic - related concepts

The atomic number ($Z$) is equal to the number of protons. For a neutral atom, the number of electrons is equal to the number of protons. The mass number ($A$) is the sum of protons and neutrons ($A = p + n$), and the isotope notation is $^{A}_{Z}X$, where $X$ is the chemical symbol.

Step2: For Lithium - 7

Lithium has an atomic number of 3. So for $Li - 7$:
Isotope notation: $^{7}_{3}Li$. Atomic number ($Z$) = 3, number of protons = 3, number of electrons = 3 (since it's neutral), number of neutrons = mass number - number of protons = $7 - 3=4$.

Step3: For the isotope with mass number 16 and 8 protons

The atomic number is equal to the number of protons, so atomic number ($Z$) = 8. The element with atomic number 8 is oxygen. Isotope name: Oxygen - 16, isotope notation: $^{16}_{8}O$, number of electrons = 8 (neutral atom), number of neutrons = mass number - number of protons = $16 - 8 = 8$.

Step4: For $^{60}_{28}Ni$

Atomic number ($Z$) = 28, number of protons = 28, number of electrons = 28 (neutral atom), number of neutrons = mass number - number of protons = $60 - 28=32$.

Step5: For the isotope with 25 protons and 28 neutrons

Atomic number ($Z$) = 25, the element is manganese. Mass number = number of protons+number of neutrons = $25 + 28=53$. Isotope name: Manganese - 53, isotope notation: $^{53}_{25}Mn$, number of electrons = 25 (neutral atom).

Step6: For the isotope with mass number 24 and 11 electrons

Since number of electrons = number of protons for a neutral atom, number of protons = 11. The element is sodium. Atomic number ($Z$) = 11, number of neutrons = mass number - number of protons = $24 - 11 = 13$. Isotope name: Sodium - 24, isotope notation: $^{24}_{11}Na$.

Isotope Name	Isotope Notation	Atomic Number	Mass Number	# Protons	# Electrons	# Neutrons
Oxygen - 16	$^{16}_{8}O$	8	16	8	8	8
Nickel - 60	$^{60}_{28}Ni$	28	60	28	28	32
Manganese - 53	$^{53}_{25}Mn$	25	53	25	25	28
Sodium - 24	$^{24}_{11}Na$	11	24	11	11	13

Answer:

Isotope Name	Isotope Notation	Atomic Number	Mass Number	# Protons	# Electrons	# Neutrons
Oxygen - 16	$^{16}_{8}O$	8	16	8	8	8
Nickel - 60	$^{60}_{28}Ni$	28	60	28	28	32
Manganese - 53	$^{53}_{25}Mn$	25	53	25	25	28
Sodium - 24	$^{24}_{11}Na$	11	24	11	11	13