Questions tagged [elements]

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108
votes
6answers
51k views

Why are most metals gray/silver?

Why do most metals (iron, tin, aluminum, lead, zinc, tungsten, nickel, etc.) appear silver or gray in color? (What atomic characteristics determine the color?) What makes copper and gold have ...
36
votes
3answers
33k views

What is the origin of elements heavier than iron?

In all the discussions about how the heavy elements in the universe are forged in the guts of stars and especially during a star's death, I usually hear that once the star begins fusing lighter atoms ...
11
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2answers
585 views

Is this a correct demonstration for why elements above untriseptium cannot exist?

With the confirmation that elements 113, 115, 117, and 118 are indeed fundamental elements that are now to be named on the periodic table, the next question is: what is the highest atomic number ...
62
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6answers
17k views

What enables protons to give new properties to an atom every time one is added?

How does adding one more particle to the nucleus of an atom give that atom new properties? I can see how it changes it's mass, that's obvious... But how does it give that new atom different properties ...
2
votes
4answers
414 views

Can nuclear transmutation be observed in real time?

Ignoring the quantum zeno effect (if possible?), can we observe in real-time the transformation of one element to another? I'm talking about an amount visible to the naked eye where one could see ...
104
votes
11answers
19k views

Why do fusion and fission both release energy?

I only have high school physics knowledge, but here is my understanding: Fusion: 2 atoms come together to form a new atom. This process releases the energy keeping them apart, and is very energetic. ...
11
votes
5answers
22k views

Why is spectrum obtained by sunlight, said to be continuous?

My teacher spoke about atomic spectra today, and he explained that, unlike the spectrum obtained by analyzing the sunlight, the spectra of atoms are not continuous. I have a question about this - ...
10
votes
1answer
14k views

What is so special about iron?

I remember reading something about how iron was a highly stable element. Ever since then, I have looked at iron fry pans with new-found respect. However, in a recent discussion I was unable to ...
14
votes
1answer
653 views

Island of Stability

When I was much younger, I remember being fascinated by the thought of an Island of Stability at very high atomic numbers. However, I have not heard much on this and I was wondering Did this idea ...
9
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3answers
4k views

Why are synthetic elements unstable?

So far 20 synthetic elements have been synthesized. All are unstable, decaying with half-lives between years and milliseconds. Why is that?
55
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3answers
8k views

Why is hydrogen the most abundant element in the Universe?

Hydrogen is the most abundant element in nature. Does cosmological nucleosynthesis provide an explanation for why is this the case? Is the explanation quantitatively precise?
14
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2answers
4k views

Why heavy elements don't sink to the core?

If earth assembled out of space dust, how come we find heavy elements like gold, silver, uranium and bunch of others that are heavier than iron on the surface? I mean silicon (Si mass 28.084) being ...
11
votes
1answer
166 views

Was helium hydride really the first molecule?

This press release by NASA: https://www.nasa.gov/feature/the-universe-s-first-type-of-molecule-is-found-at-last/ When the universe was still very young, only a few kinds of atoms existed. ...
3
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1answer
1k views

Is the rarity of elements related to their position on the periodic table?

I understand that most of the matter in the universe (aside from dark matter and energy of course) is hydrogen (74%) and helium (23-25%), leaving the remainder of the elements at only a few percent. ...
2
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2answers
369 views

Is there a limit of electrons a single hydrogen atom can have?

Is there a limit of electrons a single hydrogen atom can have? If so what is it? why? Is the the answer to why scalable to helium?
3
votes
2answers
812 views

How massive can an atom get?

After reading this thread, it appears to me that creating a new element is a game of chance some sort of an art. It also appeared to me that the higher you go, the harder it is to make an element. ...
33
votes
5answers
2k views

Why is argon a noble gas but not, say, beryllium or palladium?

Why is argon a noble gas given that the 3d subshell is still empty? More generally, why is it that the filling of a p sub-shell makes an element noble rather than s, d, or f sub-shells, or completed n-...
19
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9answers
3k views

Were alchemists right? [closed]

When I was in school, I learned about alchemists, a group of scientists who sought a way to convert other materials into gold. They were never successful, so whenever I studied or read about them, ...
26
votes
3answers
4k views

Why the distribution of elements on Earth?

I've been wondering exactly why the elements are distributed the way they are on Earth. The heavier elements have their origins in the centers of stars, or in supernovae. After the death of the stars, ...
17
votes
4answers
8k views

Why does amount of protons define how matter is?

My question might sound convoluted but my mind is twisting right now so my apologies in advanced. Why is it that when I have one proton and one electron it is Hydrogen a clear flammable gas, and ...
6
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2answers
1k views

Is it possible to create a new element that doesn't exist in the universe?

When I say something new I do not refer to something already made like H,O etc and when I mean something new I do not refer to a transformation like tritium to helium and gold. If so how ?(I mean is ...
22
votes
1answer
3k views

When will hydrogen no longer be the most abundant nucleus?

In a recent question, we learned why hydrogen is currently the most abundant nucleon or element in the universe. Here I ask a follow-up: For how long will hydrogen be the most abundant nucleus? It ...
10
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4answers
7k views

Is there a Tungsten alloy more dense than gold?

This thought came from researching a previous question. In the spirit of our get-rich-quick scheming, I looked up element densities and prices near gold. Element Density ($g/cm^3$) Value ($\$/kg$) ...
4
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2answers
53 views

Can you expect to see Island of Stability nuclei in matter flung off of neutron stars?

Apparently, merging neutron stars fling off baryon-rich matter that condenses into heavy elements, and this has been observed electromagnetically. It's not clear to me from the above sources whether ...
3
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1answer
3k views

What is the heaviest element possible produced in a supernova?

So, I would imagine this question would have been asked here long ago but the suggested questions and Google is really letting me down now. So, as far as I can tell Plutonium is the heaviest naturally ...
3
votes
1answer
187 views

Why are some elemental materials grey?

How does grey occur in elemental materials such as metals? I believe that grey arises from the simultaneous reflection and absorption of all colors of the spectrum (in different atoms of course), as ...
1
vote
1answer
645 views

Heavy Element Production from Supernova

When considering super massive stars going supernova, what are the heaviest elements that are predicted to be able to be created? So if the star VY Canis Majoris (1200 suns) were to go supernova, what ...
0
votes
1answer
286 views

Grounds state of carbon - Hunds Rule

I have a question about Hund's second rule for the ground state of carbon. Why is it that when S=1, L has to be 1 instead of 2? I don't get the whole symmetric/ antisymmetric argument. Why is L=2 ...
0
votes
1answer
93 views

When you see the atomic mass number for an element, does it take into account the atomic mass defect?

Sometimes I read that the official atomic mass number for an element on the periodic table only includes natural isotope ratios, other times I read that atomic mass defect, number of electrons, etc. ...
0
votes
2answers
117 views

In what sense are boron and carbon the simplest examples of degenerate atomic ground states?

According to this accepted answer, the most simple example of two atoms with degenerate ground states are boron and carbon. But hydrogen is the simplest of all which has the ground state configuration ...
0
votes
1answer
2k views

Reference for phase diagrams of elements [duplicate]

I am trying to answer this question: What is the pressure inside a sealed container with liquid nitrogen at room temperature? Can you help me find a good online reference for phase diagrams. I am ...