Physical Chemistry : Other Atomic Concepts

Study concepts, example questions & explanations for Physical Chemistry

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Example Questions

Example Question #21 : Atoms And Elements

Which of the following represents the alkaline earth metal with the greatest atomic number?

Possible Answers:

Correct answer:

Explanation:

Alkaline earth metals are group II elements; among them, radium has the largest atomic number.

Example Question #2 : Other Atomic Concepts

Which of the following isotopes has the most neutrons?

Possible Answers:

 

Correct answer:

 

Explanation:

 this notation is commononly used in chemistry where  represents the mass number, and  represents the atomic number of element .

To find the number of neutrons in each isotope, subtract the atomic number from the mass number.

Thus for , the number of neutrons is 67. This isotope has the most neutrons among the answer choices.

Example Question #1 : Other Atomic Concepts

How many protons, neutrons and electrons are there in a neutral atom of the copper  isotope represented by a mass number of 65 and an atomic number of 29?

Possible Answers:

Protons: 29

Neutrons: 36

Electrons: 29

Protons: 29

Neutrons: 29

Electrons: 29

Protons: 36

Neutrons: 36

Electrons: 36

Protons: 29

Neutrons: 29

Electrons: 36

Protons: 36

Neutrons: 29

Electrons: 29

Correct answer:

Protons: 29

Neutrons: 36

Electrons: 29

Explanation:

The number of protons for any atom is the same as the atomic number on the periodic table. Therefore, any isotope of copper will have 29 protons. Since the atom is neutral, the number of protons must be equal to the number of electrons. To find the number of neutrons, subtract the number of protons from the mass number to get 36 neutrons.

Example Question #61 : Nuclear, Quantum, And Molecular Chemistry

An ion from a given element has 13 protons and 10 electrons. What is the symbol of the ion? 

Possible Answers:

Correct answer:

Explanation:

The charge on the ion is equal to the difference between the number of protons and electrons:

The element has 13 protons, which means its atomic number is also 13. Thus this element is aluminum.

Example Question #62 : Nuclear, Quantum, And Molecular Chemistry

How many protons, neutrons and electrons are there in a neutral atom of the isotope of lithium-6?

Possible Answers:

Protons: 6

Neutrons: 3

Electrons: 3

Protons: 3

Neutrons: 6

Electrons: 3

Protons: 6

Neutrons: 6

Electrons: 3

Protons: 3

Neutrons: 3

Electrons: 3

Protons: 6

Neutrons: 3

Electrons: 6

Correct answer:

Protons: 3

Neutrons: 3

Electrons: 3

Explanation:

The number of protons is equal to the atomic number on the periodic table. For lithium, this number is 3. Since this isotope is neutral, the number of electrons must be equal to the number of protons. To find the number of neutrons, subtract the number of protons from the mass number to obtain 3. The notation "lithium-6" indicates that the mass number of this isotope is 6.

Example Question #3 : Other Atomic Concepts

An ion of a given element has 35 protons and 36 electrons. What is the symbol of the ion? 

Possible Answers:

Correct answer:

Explanation:

The charge on the ion is equal to the difference between the number of protons and electrons.

The element has 35 protons, thus its atomic number is 35, which corresponds to bromine. 

Example Question #2 : Other Atomic Concepts

The __________ Principle states that electrons fill lower energy levels before filling higher energy levels and __________ Rule says that electrons fill electron orbitals within a subshell singly if possible before pairing up.

Possible Answers:

Planck . . . Hund

Aufbau . . . Hund

Hund . . . Aufbau

Maxwell . . . Avogadro

Avogadro . . . Planck

Correct answer:

Aufbau . . . Hund

Explanation:

Aufbau's Principle says that electrons fill lower energy levels first. Hund's Rule dictates that electrons fill singly if possible.

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