The center of the sun is the hottest part (at around 15 million Kelvins, or 27 million degrees Fahrenheit). The temperature then drops to 5,800 K (10,000 degrees F) at the visible surface, although the corona (the part just above the surface, where solar flares are), can get much hotter (2 million K, or 3.6 million degrees F).
What is the hottest part of Sun?
The center of the sun is the hottest part (at around 15 million Kelvins, or 27 million degrees Fahrenheit). The temperature then drops to 5,800 K (10,000 degrees F) at the visible surface, although the corona (the part just above the surface, where solar flares are), can get much hotter (2 million K, or 3.6 million degrees F).
What is the difference between cathode rays and beta rays?
cathode 'rays' were observed in electrical
experiments because of their fluorescent effect near a negatively charged plate (called the
cathode) in a vacuum. They were only later found to be negatively charged electrons emitted
from negatively charged plates and accelerating toward positively charged ones. (Like
charges repel, unlike charges attract.)
Beta 'rays' were first observed being emitted from certain unstable (radioactive) isotopes, and behaved unlike the alpha and gamma radiation also found in radioactivity. It wasn't until later that both alpha and beta 'radiation' were discovered to actually be particles; only gamma rays consist of true electromagnetic radiation. Beta 'rays' are actually electrons ejected from decaying neutrons, and are now more often referred to as Beta emission or Beta particles.
So electrons can be described differently, not based on WHAT they are but HOW they are created or observed.
Beta 'rays' were first observed being emitted from certain unstable (radioactive) isotopes, and behaved unlike the alpha and gamma radiation also found in radioactivity. It wasn't until later that both alpha and beta 'radiation' were discovered to actually be particles; only gamma rays consist of true electromagnetic radiation. Beta 'rays' are actually electrons ejected from decaying neutrons, and are now more often referred to as Beta emission or Beta particles.
So electrons can be described differently, not based on WHAT they are but HOW they are created or observed.
How fast do electrons travel when moving as an electrical current through copper wire?
The actual velocity of electrons through a conductor is
measured as an average speed called drift velocity. This is because
individual electrons do not traverse straight
line paths in conductors, instead they move in a random zig-zag motion, changing
directions as they collide with atoms in the conductor. Thus, the
actual speed of the electrons through the conductor is very
small in the direction of current.
For example, the drift speed through a copper wire of cross-sectional area 3.00 x 10-6 m2, with a current of 10 A will be approximately 2.5 x 10-4 m/s or about a quarter of a milimeter per second.
For example, the drift speed through a copper wire of cross-sectional area 3.00 x 10-6 m2, with a current of 10 A will be approximately 2.5 x 10-4 m/s or about a quarter of a milimeter per second.
What is Plasma?
A plasma (or, more properly, an electromagnetic plasma) is a phase of matter that has enough energy for the electrons to separated from the nucleus. It consists of independently moving electrons and nuclei, and thus has some rather interesting properties, such as very good magnetic shielding. It can be found in places such as the center of the sun, and also, in small quantities, surrounding a lightening bolt.
Many people consider solid, liquid, gas and plasma to be the only four phases of matter. This is not true, as there exist many others, but they are generally more exotic with names like hadron gas or Bose-Einstein Condensate.
How did atom obtain its name?
The word is derived from the Greek word "atomos", meaning indivisible. The concept of the atom originated round 440 BC. In Greek, the prefix "a" means "not" and the word
"tomos" means cut. Word "atom" therefore comes from "atomos", a Greek
word meaning uncuttable.
In 1803, John Dalton formulated the "atomic theory" of matter based on experiments that quantified the weights of elements formed when compounds were broken down. Based on experimental evidence, Dalton proposed that atoms really do exist as fundamental units of all elements.
Twentieth century physics was able to probe atoms and prove that they are not, in fact, indivisible. But the name stuck, and still has meaning in that atoms are the smallest, indivisible part of any element. If you do divide them into smaller pieces of protons, neutrons and electrons, you no longer have the original element.
In 1803, John Dalton formulated the "atomic theory" of matter based on experiments that quantified the weights of elements formed when compounds were broken down. Based on experimental evidence, Dalton proposed that atoms really do exist as fundamental units of all elements.
Twentieth century physics was able to probe atoms and prove that they are not, in fact, indivisible. But the name stuck, and still has meaning in that atoms are the smallest, indivisible part of any element. If you do divide them into smaller pieces of protons, neutrons and electrons, you no longer have the original element.
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