Questions tagged [atoms]

Smallest particle still characterizing a chemical element. It consists of a small nucleus charged positively, carrying almost all of the atom's mass, with electrons surrounding it. This tag should be applied to questions that specifically concern atoms or their properties. For the charged particles, please use [ions] instead. If your question is specifically about [protons], [neutrons], or [electrons], use those tags instead.

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56 views

Atomic Orbital and Wave Function

I was reading about the atomic orbital in my chemistry textbook. It says that the atomic orbital (psi) is a mathematical wave function that depends on the coordinates of the electron. It is also ...
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Atomic emission spectrum assumption n_f = 3

It's a standard question on the atomic emission spectrum. An atomic emission spectrum of hydrogen shows three wavelengths: 1875 nm, 1282 nm, and 1093 nm. Assign this wavelengths to transitions in ...
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Ground state term symbol, why is $L = |M_L|$, if L must be a maximum?

I'm trying to understand how to predict ground state term symbol of atoms. After finding the biggest S, why the biggest L will be $L = |M_L|$, where $M_L = \sum m_l$? I know this rule works to ...
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Force on an electron in a given orbital [closed]

I was wondering whether there is any quantum mechanical equation to describe the force on a given electron in a given orbital of an atom (lets say, for the simplest case, for hydrogen atom). Also if ...
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Why is atomic number unique? [closed]

We all know that atomic number of an atom is "unique" just like fingerprint. And no two elements can have same atomic number. But how can we be So sure that no two elements can have same atomic number?...
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Isotopes and elements [closed]

this is a gold bar. If we look at its structure, will we see that there are atoms that have a different number of neutrons (aka isotopes) (as far as I'm concerned, an isotope is an atom with a ...
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14 views

Electron shells and subshells energies [duplicate]

According to what i learned in university, the energy of orbitals increases when the principal quantum number n increases. Also, in a given shell, s orbitals have lower energy than p orbitals which ...
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1answer
91 views

Why does zinc sulfide glow when hit by electrons? [duplicate]

In cathode ray tube experiment in order to check the direction of flow of electrons a hole was made in a note and behind it phosphorescent material zinc sulfide it was coated. Why does zinc sulfide ...
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267 views

How does de Broglie actually prove Bohr's postulates?

We know Bohr said that the angular momentum of an electron is an integral multiple of $nh/(2π).$ And in de Broglie's wave equation, he said the circumference of the path of the electron traveling as a ...
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Shielding effect on an electron

Whenever we calculate the screening constant on an $\ce{f block} $ element, we start calculating from the electron present in the $\ce{(n-2)f orbital}$ and then leftwards. I was a bit confused that ...
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Is there any formula for finding out probable distance of orbitals or do I just remember the values? [closed]

Like, do I need to just remember that it is less in 3d than 3s and so on?
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50 views

Antimatter molecules properties [closed]

Do the antimatter molecules have the same chemical properties with matter molecules?Should we define electropositivity for antimatter molecules since the chemical bonding would be between positrons?
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Can Rydberg constant be in joules?

In my textbook (Chemistry Part - I for Class XI published by NCERT), there is an equation for the energy of an electron in an energy state: $$E_n = -R_\mathrm H\left(\frac{1}{n^2}\right)$$ and there ...
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2answers
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Why there is a difference between atoms and chemicals

I recently asked this about why we call things "isotopes" and "elements" (atoms) instead of just having it be a bunch of particles bundled together in different numbers. This makes me wonder about ...
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428 views

Cause of continuous spectral lines [closed]

We know different types of atoms have different spectral lines. But what exactly are the spectral lines representing? What causes white light to have a continuous spectra while other atoms show ...
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64 views

How can the potential energy at the infinite energy level in an atom be zero?

I have recently learnt about atomic structure and the Bohr model of the atom and have observed a discrepancy between it and my previous knowledge based on physics. For simplicity, assume the atom is ...
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224 views

Can 2 dz2 orbitals form a π bond?

Usually , d orbitals overlap sideways along a common internuclear axis, but drawing and checking for dz2 , it always seems to form a sigma bond or null overlap. Is this because it doesn't have any ...
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Strongest overlap among s–s, p–p, s–p [duplicate]

So, I was wondering, when overlap of orbitals takes place, among s–s, s–p, p–p which type of overlapping is stronger? Because in s–s more volume is being used in overlap, but the electron density is ...
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Why is the dz2 orbital so different from the rest?

What makes dz2 orbital so special? Although degenerate with other d orbitals, It has no nodal planes, instead it has 2 nodal "cones". Instead of having 4 lobes, it has 2 lobes and 1 ring. Also, ...
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Atomic number ranges in “integral units”?

My textbook says the following: For an electrically neutral or complete atom, the atomic number also equals the number of electrons. This atomic number ranges in integral units from 1 for hydrogen ...
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1answer
48 views

Doubt regarding timeline of events and development of theories

I recently studied Zaitsev's and Hoffman's rules for deciding which product is formed via elimination and noticed that the rules for formulated much before the discovery of electrons and any ...
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127 views

Does dilithium exist? [duplicate]

Lithium has two electrons in $\mathrm{1s}$, filling the first energy level; and one valence electron in $\mathrm{2s}$. Could two $\ce{Li}$ atoms form a bond to create $\ce{Li2}$; like $\ce{O2}$ or $\...
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how does mass of carbon 12 is like this? [duplicate]

1u is defined as per carbon 12 so 1 atom of c have 6 neutrons and 6 protons both having mass more than 1u (Google)so total mass of carbon 12 is more then 12u (also there would be some mass of ...
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Textbook Claim: “… in all cases it is the electrostatic force acting between charged particles that is responsible for all the forms of bonding.” [duplicate]

I am reading an introductory semiconductor physics textbook. The textbook states the following: Several types of atomic bonding have been identified, including ionic, covalent, van der Waals, ...
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Why does ionisation energy to remove electrons from the same subshell increases? [closed]

Electrons in the same subshell possesses the same energy. So why does ionisation energy to remove electrons from the same subshell increases? For example, $\mathrm{2s^2}$ has two electrons. Since ...
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1answer
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Periodic Table and Atomic Radius

Well Wikipedia says that the atomic radius is lowered for elements in a group closer to noble gases (same row). It also says that those elements want to keep their valence electrons more than metals, ...
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1answer
121 views

Radius with Bohr model [closed]

$$r_n = \left(\frac{h^2}{4\pi^2me^2}\right)\times\frac{n^2}{Z} $$ Would I be able to calculate the radius of sodium ion ($\ce{Na+}$) with the help of the above Bohr atomic model formula?
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Identifying orbital given electron probability density plot

Being a high-school student, I only have a qualitative understanding of the wave mechanical model of atom. Below are my inferences regarding the plot shown in the above picture: The concerned ...
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54 views

Does one atom of an element show the properties of a bulk of that element? [duplicate]

For example, does one atom of gold have a golden color?
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How did scientists discover the concepts of anode and cathode without knowing about electrons? [closed]

Scientists researched electrons and came to know about electrons after the battery was developed as we can see in the JJ Thomson's model that he used the cathode and anode. My question is that that if ...
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1answer
246 views

Strong or weak force between protons and neutrons?

I had learned that what keeps the protons and neutrons bound is the strong force and the weak force has to do with radioactive decay. but today I read an article from Science Daily that contradicts ...
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1answer
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Does berylium gain or lose electrons?

Does beryllium want to gain or lose electrons? I know it has 4 protons, 2 valence electrons, and it will gain or lose 2 electrons, but what is it?
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111 views

Confusion about electron arrangement in elements

My textbook says, "The first shell can hold only 2 electrons. The second and subsequent shells can hold 8 electrons to give a stable noble gas arrangement." Can someone explain me if it is MAXIMUM 8 ...
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Is there radioactivity at absolute zero?

Theoretically, will a radioactive material still be radioactive at absolute zero? What would happen at the lowest realistic temperatures we have ever achieved? Will radioactivity stop at absolute ...
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Understanding water models?

I generally work on fluid flow, so some basic concepts in chemistry are new to me. Work I'm doing requires use of molecular dynamics (MD) to do classical potential simulations of water–NaCl systems ...
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285 views

Is the maximum oxidation state of an element equal to it's valency?

I know maximum oxidation state has a sign and valeny doesn't.... But, if we remove the sign then, would it be equal to the valency of an element? I earlier assumed that valency was equal to the ...
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Question about the definition of an isotopes

My answer was as follows : atoms of the same element with differrnt relative atomic masses. However in the mark scheme the answer was simply : atoms of the same element with different masses. Was ...
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2answers
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Can there be any substance whose number of electrons and protons are different at neutral state

I want to ask that if there any substance that has the different number of electrons and protons at its neutral state
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28 views

Atoms in Solar Cells

An electric field in solar cells is created through photons knocking electrons off of atoms. What happens to the positively charged atoms once the electrons have been knocked off? Furthermore, are the ...
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1answer
422 views

How are the molar mass and molecular mass of any compound numerically the same?

This observation is really annoying me, and the internet isn't providing me with any solid answers. Either their definitions of molar mass completely differ, or they don't stick to their own ...
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Hydrogen molecule potential energy graph

In the above graph, I was confused at the point where the internuclear distance increases and potential energy become zero. Though internuclear distance is very small and potential energy has ...
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82 views

Atomic weight = expected weight?

The atomic weight of an element, is it accurate to say that another way to think of it is the expected value of that element's weight if we were to sample one at random from the environment? Are man-...
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What is the true depiction of the periodic table?

Normally with the periodic table the lanthanide series is separated out because it's long and would make the table wide. I looked for an expanded version and found this: I found it kind of strange ...
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How did early chemists measure mass of atoms?

Here a book says that Berzelius measured atomic masses using a simple lab and his measurements was so close to modern results. Can someone explain how a person living in 19th century was able to ...
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364 views

Why do atoms have electron Affinity? [duplicate]

Atoms are stable so how can they pull electrons i.e how do they have any electron affinity at all?
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Is neutron a compressed form of hydrogen atom?

As I know: $E_\mathrm{p} = \pu{938.272 MeV}, \quad E_\mathrm{e} = \pu{0.511 MeV}, \quad E_\mathrm{n} = \pu{939.565 MeV}$ $E_\mathrm{n} − (E_\mathrm{p} + E_\mathrm{e}) = \pu{0.782 MeV}$ $M_\...
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Rutherford's alpha particle scattering experiment for sheets made of different metals [closed]

The correct order of increasing number of alpha particles passing undeflected through the foils of Au, Ag, Cu and Al of 1000 atoms thickness each in an alpha scattering experiment of Rutherford would ...
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As an atom get's bigger (on increasing atomic no.) , electrons have to move faster and faster around the nucleus, Why?

Does speed even make sense at such small scales ? Heisenbergs Uncertainty principle ?
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Trying to understand the contradiction in the data of Proust/Dalton/Berzelius vs Gay-Lussac

I am trying to understand some of the historical context behind the discovery of atoms (pre-Avogadro). In particular, I am getting stuck in reading the following documents: http://physics.unl.edu/~...
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Are ions actually charged particles?

For instance, if an atom loses an electron and becomes a cation, such as sodium, how does that make the sodium atom positively charged? The sodium's atomic radii decreases due to less electron-...