5.2 Quantum Theory and the Atom

The lyman series is caused by electron transitions from Bohr's higher energy orbits to the n=1 orbit.

According to the Bohr model shown in Figure 5.23, what type of electron-orbit transitions produce the ultraviolet lines in hydrogen's Lyman series?

Electrons move in circular orbits around the nucleus

According to the Bohr model, how do electrons move in atoms?

Bohr model: the electron is a particle; they hydrogen atom has only certain allowable energy states. Quantum mechanical model: the electron is a wave-particle phenomenon; an electron's energy is limited to certain values. Also, the quantum mechanical model makes no assertions regarding the electron's path around the nucleus.

Compare and contrast Bohr's model and the quantum mechanical model of the atom

The wavelength of the moving soccer ball is much smaller than the wavelengths of visible light. The moving soccer ball's wavelength is too small to see or detect

Differentiate between the wavelength of visible light and the wavelength of a moving soccer ball

First energy level, s Second energy level, s and p Third energy level, s, p, and d Fourth energy level, s, p, d and f Each s sublevel is related to a spherical s orbital. Each p sublevel is related to three dumbell-shaped oribitals on the x, y, and z axis

Enumerate the sublevels contained in the hydrogen atom's first four energy levels. What orbits are related to each s sublevel and each p sublevel?

Because only certain atomic energies are possible, only certain frequencies or radiation can be emitted from an atom.

Explain the reason, according to Bohr's atomic model, why atomic emission spectra contain only certain frequencies of light.

An electron has wave-particle characteristics and does not have a single, definite location in space. The Heisenberg uncertainty principle states that it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time

Explain why the location of an electron in an atom is uncertain using the Heisenburg uncertainty principle and de Broglie's wave-particle duality. How is the location of electrons in atoms defined?

The quantum mechanical model gives no description of the electrons' paths

How does the quantum mechanical model of the atom describe the paths of an atom's electrons?

eight electrons

How many electrons can be contained in all the orbitals related to an argon atom's third energy level?

Energy level 1 has one sub level, energy level 2 has two sub levels, energy level 3 has three sub levels.

How many energy sublevels are contained in each of the hydrogen's atom's first three energy levels?

for n = 7, radius: 2.59 nm for n = 1, radius: 0.0529nm 2.59 nm / 0.0529 nm = 49.0 times larger

Use the information in table 5.1 to calculate how many times larger the hydrogen atom's seventh Bohr radius is than its first Bohr radius

their shapes

What do the sub level designations s, p, d, and f specify with respect to the atom's orbitals?

The quantum number, n, specifies the electron's orbit

What does n designate in Bohr's atomic model?

n represents an orbital's principle quantum number, which indicates the relative size and energy of the orbital

What does n represent in the quantum mechanical model of the atom?

a three-dimensional region around the nucleus describing an electron's probably location

What is an atomic orbital?

An atom's ground state is its lowest energy state, while any energy state higher than the ground state is an excited state

What is the difference between an atom's ground state and an excited state?

two electrons

What is the maximum number of electrons an orbital can contain?

the quantum mechanical model of the atom; Schrodinger

What is the name of the atomic model in which electrons are treated as waves? Who first wrote the electron wave equations that led to this model?

Their wavelengths are too small to be seen.

Why do we not notice the wavelengths of moving objects such as automobiles?

The photon required to measure an electron's velocity or position changes both the position and velocity of the electron

Why is it impossible to know precisely the velocity and position of an electron at the same time?