Chemistry Concepts Flashcards

Questions and Answers

Why do atoms emit light energy according to the Bohr model?

Because an electron has fallen to a lower energy state.

Why does arsenic produce a blue flame when heated, while calcium produces an orange-red flame?

Because the energy level difference between orbits is greater in arsenic than in calcium.

According to Schrodinger, the accuracy with which we can measure the momentum of an electron increases _______

none of the above

What can quantum numbers tell us?

The probable location of an electron. Signup and view all the answers

What is Hund's Rule?

Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin. Signup and view all the answers

Which two elements have the same ground state electron configuration?

No two elements. Signup and view all the answers

The ______ subshell contains seven orbitals.

f Signup and view all the answers

What does the angular quantum number (l) designate?

Shape of orbitals. Signup and view all the answers

What does n = principal represent?

Energy level/distance from nucleus. Signup and view all the answers

What does ml represent?

Orientation of orbital space. Signup and view all the answers

What does ms represent?

Direction of orbital spin. Signup and view all the answers

What cannot exist?

1p. Signup and view all the answers

At max, an f-orbital can hold _ electrons, a d-orbital can hold electrons, and a p-orbital can hold ___ electrons.

14, 10, 6 Signup and view all the answers

What is the element that has a valence configuration of 5s^2?

Ba. Signup and view all the answers

How many quantum numbers are necessary to designate a particular electron in an atom?

<ol start="4"> <li></li> </ol> Signup and view all the answers

Which of the following is the correct quantum numbers to designate a p orbital?

2 1 1. Signup and view all the answers

Discuss one example of Rutherford's model violating the laws of physics and how the Bohr model improved on Rutherford's model.

Coulomb's law predicts electrons would pull into nucleus due to radiation of energy. Signup and view all the answers

Explain two major differences between the classical models of Bohr and Rutherford and the quantum mechanical view of the atom.

QM allows electrons to have both wave and particle-like properties and explains how most electrons are behaving rather than the behavior of specific electrons. Signup and view all the answers

Calculate the wavelength of an atom of silicon moving at a velocity of 3.0E4 m/s.

Wavelength = h/mv. Signup and view all the answers

How did the Bohr model explain the emission spectra produced by atoms?

Spectral lines are produced when electrons drop from higher energy orbits to lower energy orbits. Signup and view all the answers

Which of the following is not true about the Bohr model of the atom?

It could not explain why different elements produced different spectra. Signup and view all the answers

Which of the following best summarizes the quantum mechanical view of an electron?

Act like wave and particle. Signup and view all the answers

Electrons occupying the same energy level and orbital type share which of the following sets of quantum numbers and values?

n and l. Signup and view all the answers

The _____ subshell contains 3 orbitals.

p Signup and view all the answers

The second energy shell can accommodate a maximum of _ orbitals and __ electrons.

3, 6 Signup and view all the answers

What information do electron configurations provide about an atom?

The probable location of each electron in the atom. Signup and view all the answers

What is the Aufbau rule?

Electrons fill the lowest energy level first. Signup and view all the answers

What are ground state rules?

Fill lower first, up and down arrows, 1 before 2. Signup and view all the answers

In a ground state cobalt atom, Co, the _____ subshell is partially filled.

3d Signup and view all the answers

How many different principal quantum numbers can be found in the ground state electron configuration of oxygen?

<ol start="2"> <li></li> </ol> Signup and view all the answers

Explain why atoms were expected to emit continuous spectra of energy at all times and how the Bohr model of the atom explained the unexpected spectral lines produced by atoms.

Coulomb's law predicts that electrons would be accelerating toward the nucleus and accelerating objects emit energy; Bohr's model has electrons in stable orbits at set energy levels. Signup and view all the answers

Discuss two faults of the Bohr model.

Could not explain more complex than hydrogen and relied on the idea that electrons in stable orbit somehow violate the law that they should be radiating continuous energy. Signup and view all the answers

Study Notes

Bohr Model and Light Emission

Atoms emit light energy when electrons drop to lower energy states.
Arsenic produces blue flames and calcium produces orange-red flames due to greater energy level differences in arsenic.

Quantum Mechanics Concepts

Accuracy of momentum measurements for electrons is uncertain, with the response indicating non-applicability.
Quantum numbers indicate the probable location of electrons and describe properties of orbitals.

Key Principles and Rules

Hund's Rule states that orbitals of equal energy are singly occupied before being doubly occupied, maintaining consistent electron spin.
No two elements can have the same ground state electron configuration.
The f subshell has seven orbitals, while the p subshell has three orbitals.

Quantum Number Components

Angular quantum number (l) dictates the shape of orbitals.
Principal quantum number (n) designates energy level and distance from the nucleus.
Magnetic quantum number (ml) shows orbital orientation, while spin quantum number (ms) indicates the direction of spin.

Electron Capacity in Orbitals

Maximum electron capacities: f-orbital holds 14, d-orbital holds 10, and p-orbital holds 6 electrons.

Valence Configurations

The element barium (Ba) has a valence configuration of 5s².
Four quantum numbers are necessary to define a specific electron in an atom.

Quantum Number Designation

The quantum numbers for a p orbital are designated as 2 (n), 1 (l), 1 (ml).

Rutherford and Bohr Models

Rutherford's model violates Coulomb's law due to predictions that electrons would spiral into the nucleus.
Bohr's model addresses these issues by establishing stable orbits where electrons do not radiate energy, emitting light only when transitioning between set energy levels.

Comparative Models of Atom

The quantum mechanical model allows electrons to exhibit both wave-like and particle-like properties.
It focuses on understanding the behavior of electrons collectively, rather than addressing specific electrons.

Emission Spectra Explanation

Spectral lines result from electron transitions from higher to lower energy orbits.
The Bohr model cannot adequately explain different spectra across elements.

Quantum Mechanical View

Electrons are best described as exhibiting both wave and particle characteristics.
Electrons within the same energy level and type share quantum numbers n and l.

Electron Configuration Characteristics

Electron configurations reveal electron locations within an atom.
Aufbau principle dictates that electrons fill the lowest energy levels first, while ground state rules align with this filling sequence and spin orientation.

Ground State of Cobalt and Oxygen

Ground state cobalt (Co) has a partially filled 3d subshell.
In its ground state, oxygen has two distinct principal quantum numbers.

Emission Spectra Expectations

Early expectations suggested continuous spectra due to accelerating electrons drawing near the nucleus.
Bohr's model countered this by proposing electrons reside in stable orbits, only emitting energy when transitioning between orbits.

Faults of the Bohr Model

Bohr's model fails to explain the behavior of complex atoms beyond hydrogen.
The model's assumption of stable orbits conflicts with the principle that electrons should continuously radiate energy.

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Test your knowledge on key chemistry concepts with these flashcards. Learn about atomic behavior, energy levels, and flame tests as explained by the Bohr model and other theories. Perfect for last-minute studying before your exam!