Why Does Lithium Stay on the Surface of the Sun?

  • Context: Undergrad 
  • Thread starter Thread starter sawtooth500
  • Start date Start date
  • Tags Tags
    Lithium Surface
Click For Summary

Discussion Overview

The discussion centers around the presence of lithium on the surface of the Sun and the mechanisms that prevent heavier elements, like uranium, from sinking to the core. Participants explore the effects of temperature, kinetic energy, and gravitational forces in the context of stellar physics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that lithium remains on the Sun's surface due to the high temperatures providing enough kinetic energy to counteract gravitational effects.
  • Another participant questions whether this principle applies to all elements, specifically asking about uranium and its behavior if introduced into the Sun.
  • A different perspective suggests that uranium would turn into plasma and could be distributed throughout the Sun due to convection currents, although the certainty of this claim is not established.
  • One participant mentions that significant gravitational acceleration would be necessary for heavier atoms to sink, referencing the principle used in ultracentrifuges for isotope separation.

Areas of Agreement / Disagreement

Participants express varying views on the behavior of different elements in the Sun, with no consensus reached regarding the fate of uranium or the general applicability of the kinetic energy principle to all elements.

Contextual Notes

The discussion does not resolve the assumptions regarding the behavior of elements in extreme temperatures and gravitational fields, nor does it clarify the specific conditions under which heavier elements might behave differently.

sawtooth500
Messages
16
Reaction score
0
I recently saw a science documentary saying that there is a lot of lithium on the sun's surface - since lithium is heavier than H and He wouldn't it sink to the core of the sun? How does it stay on the surface?
 
Astronomy news on Phys.org
It is mainly an effect of temperature. The various nuclides that make up the sun, along with electrons (it is too hot to have atoms) have so much kinetic energy that gravity has very little effect on individual particles.
 
So is that true for all the elements? So suppose I tossed a slab of pure uranium into the sun - I am guessing it would separate the uranium into individual atoms and those would stay at the surface? Or would those sink because U is so much heavier than Li?
 
sawtooth500 said:
So is that true for all the elements? So suppose I tossed a slab of pure uranium into the sun - I am guessing it would separate the uranium into individual atoms and those would stay at the surface? Or would those sink because U is so much heavier than Li?

I think it would turn to plasma and dilute within the sun. The sun has convection currents so I would expect at least some of it to move through these and to spread throughout the outer region of the sun, but I'm not sure.
 
You would need very high gravitational accelerations to cause the heavier atoms to sink. This is the principal that ultracentrifuges use to separate different isotopes of uranium.

http://en.wikipedia.org/wiki/Gas_centrifuge
 

Similar threads

Undergrad J0524-0336, surprisingly high Li concentration
  • · Replies 2 ·
Replies
2
Views
3K
High School Process of a sun changing into a white dwarf
  • · Replies 5 ·
Replies
5
Views
2K
High School Why was the Sun's output not as intense in the past?
  • · Replies 7 ·
Replies
7
Views
1K
High School Sun's peak wavelengths and chlorophyll's green colour
  • · Replies 27 ·
Replies
27
Views
3K
Residential concrete densifier and sealer?
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Why Does the Sun Have an Orbital Period Like a Year?
  • · Replies 11 ·
Replies
11
Views
4K
High School Why does it take thousands of years for light to reach the surface of the Sun?
  • · Replies 12 ·
Replies
12
Views
3K
Lithium-6 Hydride verses Lithium-7 Hydride
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad What are the Dynamics and Impacts of a Type II Supernova?
  • · Replies 11 ·
Replies
11
Views
3K
Undergrad Could a fully convective Sun double its lifespan?
  • · Replies 21 ·
Replies
21
Views
4K