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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206 views

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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2answers
383 views

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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1answer
68 views

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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15 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
539 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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1answer
885 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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24 views

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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1answer
94 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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3answers
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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
144 views

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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2answers
617 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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0answers
147 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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0answers
47 views

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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1answer
6k views

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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1answer
58 views

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
49 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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1answer
299 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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28 views

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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1answer
133 views

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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1answer
259 views

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
46 views

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
230 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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1answer
86 views

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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1answer
123 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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1answer
87 views

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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2answers
309 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
329 views

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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1answer
186 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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4answers
5k views

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 ...
2
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1answer
69 views

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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2answers
668 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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2answers
86 views

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
89 views

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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1answer
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
851 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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1answer
11k views

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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2answers
94 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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2answers
1k views

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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1answer
175 views

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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2answers
500 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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0answers
94 views

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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0answers
183 views

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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0answers
79 views

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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1answer
176 views

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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3answers
750 views

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-...
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1answer
87 views

Finding molecules that you randomly create using a modeling kit

I recently bought https://snatoms.com/ (which is just a real-life modeling kit for atoms/molecules) and was just keen on learning about chemistry in general. I often randomly join atoms to make up ...
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0answers
224 views

Quantum Mechanical Model of An Atom, Shells, Subshells [duplicate]

I've just been introduced to the quantum Mechanical Model of an Atom, so please bear with me on this one. Are Subshells and shell physical things, like do they really exist, or is it a concept only to ...
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2answers
2k views

What is the difference between ''1 C atom and 1 mole of C atoms?'' [closed]

Does 1 C atom mean 1 single C atom out of Avogadro's number of C atoms = 1 single C atom out of 6.023 X 10^23 numbers of C atoms? Does 1 mole of C atoms mean Avogadro's number of C atoms = 6.023 X 10^...
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1answer
58 views

What makes bond break apart from heat? [closed]

What makes bonds break apart from heat? I am wondering if anyone could explain the reasons why new bonds are formed in the absence of energy. I have found that they form in order to lower the overall ...

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