We will see that the quantum numbers discussed in this section are valid for a broad range of particles and other systems, such as nuclei. Some quantum numbers, such as intrinsic spin, are related to fundamental classifications of subatomic particles, and they obey laws that will give us further insight into the substructure of matter and its interactions.
Phet explorations: stern-gerlach experiment
The classic Stern-Gerlach Experiment shows that atoms have a property called spin. Spin is a kind of intrinsic angular momentum, which has no classical counterpart. When the z-component of the spin is measured, one always gets one of two values: spin up or spin down.
Section summary
Quantum numbers are used to express the allowed values of quantized entities. The principal quantum number
$n$ labels the basic states of a system and is given by
where
$l$ is the angular momentum quantum number. The direction of angular momentum is quantized, in that its component along an axis defined by a magnetic field, called the
$z$ -axis is given by
where
${L}_{z}$ is the
$z$ -component of the angular momentum and
${m}_{l}$ is the angular momentum projection quantum number. Similarly, the electron’s intrinsic spin angular momentum
$S$ is given by
where
${S}_{z}$ is the
$z$ -component of spin angular momentum and
${m}_{s}$ is the spin projection quantum number. Spin projection
${m}_{s}\text{=+}1/2$ is referred to as spin up, whereas
${m}_{s}=-1/2$ is called spin down.
[link] summarizes the atomic quantum numbers and their allowed values.
Conceptual questions
Define the quantum numbers
$\mathrm{n,\; l,}\phantom{\rule{0.25em}{0ex}}{m}_{l}\mathrm{,\; s}$ , and
${m}_{s}$ .
For a given value of
$l$ , what are the allowed values of
${m}_{l}$ ? What are the allowed values of
${m}_{l}$ for a given value of
$n$ ? Give an example in each case.
(a) What is the magnitude of the angular momentum for an
$l=1$ electron? (b) Calculate the magnitude of the electron’s spin angular momentum. (c) What is the ratio of these angular momenta?
a submersible pump is dropped a borehole and hits the level of water at the bottom of the borehole 5 seconds later.determine the level of water in the borehole
power P = Work done per second W/ t. It means the more power, the stronger machine
Sphere
e.g. heart Uses 2 W per beat.
Rohit
A spherica, concave shaving mirror has a radius of curvature of 32 cm .what is the magnification of a persons face. when it is 12cm to the left of the vertex of the mirror
my name is Abu m.konnek
I am a student of a electrical engineer and I want you to help me
Abu
the magnification k = f/(f-d) with focus f = R/2 =16 cm; d =12 cm
k = 16/4 =4
Sphere
what do we call velocity
Kings
A weather vane is some sort of directional arrow parallel to the ground that may rotate freely in a horizontal plane. A typical weather vane has a large cross-sectional area perpendicular to the direction the arrow is pointing, like a “One Way” street sign. The purpose of the weather vane is to indicate the direction of the wind. As wind blows pa
the same behavior thru the prism out or in water bud abbot
Ju
If this will experimented with a hollow(vaccum) prism in water then what will be result ?
Anurag
What was the previous far point of a patient who had laser correction that reduced the power of her eye by 7.00 D, producing a normal distant vision power of 50.0 D for her?
What is the far point of a person whose eyes have a relaxed power of 50.5 D?
Jaydie
What is the far point of a person whose eyes have a relaxed power of 50.5 D?
Jaydie
A young woman with normal distant vision has a 10.0% ability to accommodate (that is, increase) the power of her eyes. What is the closest object she can see clearly?
Jaydie
29/20 ? maybes
Ju
In what ways does physics affect the society both positively or negatively