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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Calculating the threshold frequency and kinetic energy of emitted electrons [closed]

I was working on the following problem: The work function of sodium is $\pu{2,5 eV}$. We illuminate it with a radiation that has a wavelength of $\lambda = \pu{2.0E-7 m}$. What is the threshold ...
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Photoelectric effect problem: what is maximum wavelength for the photoelectric effect to happen? [closed]

I was working on the following problem, Find the kinetic energy of an electron removed from the surface of a certain metal by a radiation of frequency $\lambda =5\times10^{15}\; Hz $, if the ...
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Can an element be a single atom or a molecule made up of atoms of the same element?

Some online websites and some books as well suggest that elements are either atoms (e.g. Ne) or molecules (e.g. $\ce{H2}$, $\ce{O2}$). Original source: Tro, Chemistry: A Molecular Approach (2008) ...
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What is the energy difference between inner subshells?

For exemple, in silver the energy difference between the 4d 5s subshells is ≈ 4 eV (in the ultraviolet region, that's why it has no color, etc.), but what is the energy difference between some of its ...
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How do I calculate q/m? [closed]

My chemistry book (Mortimer in German) has the following question: Calculate the value q/m for the following Ions: ("mit Masse" meaning "with mass") How do I calculate q/m? Thanks ...
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where could I find the standard atomic orbital energy of all elements?

I am trying to find the standard atomic orbital energy of all elements. Here is the data I found in some old books: I am looking for some more modernized data, I tried to look for the data in the CRC ...
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What does it mean when we say an atom has infinite energy levels/shells? [closed]

My chemistry teacher told that an atom has infinite energy shells according to Bohr model , where electron reside according to its angular momentum and energy. But in lower classes/ grades I have ...
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Why do atoms make bonds? [duplicate]

I have been studying chemistry for a long time in school till now, but, what I recently realised I do not understand is why do atoms really make bonds, why do they want to gain or lose electrons or ...
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Proof for equation of radial probability distribution curve

So my textbook says the equation for this is $$P(r) = 4\pi r^2\Psi^2 $$ It also gives the volume of the shell formula $$\mathrm{d}V = \frac 43 \pi(r+\mathrm{d}r)^3 - \frac 43 \pi r^3$$ which I ...
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Size of Orbitals, Making Intuitive Sense of Quantum Model, Nomenclature of Subshells in the Quantum Model

Alright, so I am doing the Quantum Mechanical (or what some people call the Wave Mechanical model) of an atom. There's this part where we have different zones of the probablity of finding electrons, ...
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How do water vapor molecules push other air molecules away?

I've read that when water vapor enters the atmosphere, the vapor molecules push the oxygen and nitrogen molecules out of the way and occupy their space. But if water vapor molecules are lighter than ...
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Restoring potential of atoms in a solid

Above $\pu{0 K}$ the atoms in a solid are vibrating. However, what kind of potential restores each atom in the starting position? Consider the crystal lattice of NaCl. The potential energy of a $\ce{...
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Why isn't Beryllium a noble gas? [closed]

Somebody answered it before on physics StackExchange, but I couldn't follow the high-level parlance. All I could follow is that it is related to the p subshell. I cannot understand why elements form ...
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In Lanthanides, Why is electron removed from 4f before 5p? [duplicate]

I've been taught that electrons are removed first from valence shell electrons with highest energy. But In Lanthanides, for example taking configuration- [Xe]4f⁴6s², If we go to +3 Oxidation State, ...
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Why doesn't my estimation for the relative mass of a single lithium-7 atom work? [duplicate]

So I tried to calculate the relative mass of a lithium-7 atom. I added up the masses of all the protons, neutrons and electrons, like this: mass = relative mass of 3 protons + relative mass of 4 ...
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How did we find relative atomic masses in 18th century or early 19th century? [duplicate]

The atomic masses of atoms or relative atomic masses were known in the 19th century. But how did they actually calculate that relative atomic mass? What I think is that if we have a sample of an ...
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How do the odd proton-number elements originate?

I have a question about the origin of the odd proton-number elements in the periodic table, please. As it is generally thought that the big bang produces hydrogen first, and then hydrogen combined to ...
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What kind of electronic configurations are possible?

Let us take $d^6$ orbital as an example: A) ↑ | ↑ | ↑ ↓ | ↑ | ↑ | Now , this one 1 way. My Q is that how is it possible that in the 3rd box , we have a paired electron but not in the 1st one. Like it ...
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Why are the relative masses of isotopes not close to whole numbers?

Understandably, the relative atomic masses of isotopes are often not close to whole numbers as they're adjusted for isotope abudandancy eg. $A_r(Cl)\approx35.45$. However, wouldn't one expect the ...
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Can an atom bond with any other atom?

I am designing a game for students which has a sandbox for atoms to create molecules like building blocks. I have the valance of each atom mapped and they can bond with other atoms based on their ...
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What happens inside the orbital when energy provided to electron is not sufficient for it to change orbitals? [closed]

While studying the chapter called Atomic Structure, we were introduced with Bohr's model of an Atom. Even though not all of his postulates were right, I believe some were. A doubt arose in the ...
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What are the Ionic Properties of Co-ordinate Covalent Bonds? [closed]

In my 10th grade book, it says that A coordinate bond has properties of both covalent and ionic bonds. Therefore, it is also called dative or co-ionic bonds. I understand that it has properties of ...
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Shielding effect is not constant across a period [closed]

Shielding effect stays constant across a period because number of inner electrons stays the same. Well, that's not true. It only works for the period =1,2,3 but in period 4, the number of inner ...
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A better understanding of the screening effect and how it works?

What I am taught- Inner shell electrons shield the outermost electrons from the attraction of nucleus. More closer the inner shell is to the nucleus, more its shielding effect. thus $n_s > n_p > ...
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Which atom is the smallest atom?

Is hydrogen or helium the smallest atom? My teacher said that the smallest atom is the helium atom, but I think that the smallest atom is the hydrogen atom. It has a single electron and a single ...
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Why is sulphur not written as S8 here [duplicate]

I learnt that sulfur dioxide and hydrogen sulphide react to form sulfur and water. The reaction given was: $\ce{SO2 + 2 H2S -> 2 H2O + 3S}$ So why is the product sulfur written as $\ce{S}$ and not ...
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What is "gram atom of an element"? [duplicate]

I've seen so many answers on Quora that got me lost : 1st answer : The three are similar. Gram atom.... Take the atomic mass of an element and express it in grams (sodium for example atomic mass is 22....
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The necessary energy required to ionize 1g of potasium in its fundamental state if the ionization energy is given

The energy of ionization of the potassium is $\pu{6.94\cdot 10^{-19} J/atom}.$ Find the necessary energy to ionize $\pu{1 g}$ of potasium that is found on its fundamental state. Attempt. I really ...
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Comparing average radius of subshells for multielectron atoms

I recently came across a question comparing the average radius of subshells. A search on the internet gave the following result for single electron atoms: $$\langle r\rangle_{n,\,l}=\frac{a_0 n^2 \...
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How many atoms are there in single element? [closed]

Elements are chemical substances made up of the same types of atoms (atoms with the same proton number), whereas molecules are chemical compounds made up of atoms from two or more different elements. ...
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Why does increasing subshell cause ionization energy to decrease?

I know that increasing subshell decreases ionization energy; for example, going from Beryllium to Boron. I do not understand why this is. The answer my textbook (Chemistry 2e on OpenStax) gives is ...
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respective posistion of d and p orbitals in a multielectronic species

we write the electronic configuration of atoms as [noble gas core]4s2 3d10.that is that due to energy considerations(aufbau principle) in multielectronic species. what i want to know is whether the 4s ...
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Lother Mayer curve

While studying about atomic trends, I encountered the Lothar Meyer curve: If the covalent radius decreases across a period, why is the graph of atomic volume reaching local minima halfway in the ...
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The ambiguity regarding aufbau principle

According to a Blog https://ericscerri.blogspot.com/2012/06/trouble-with-using-aufbau-to-find.html written by Dr.Eric Scerri, On moving from the $\ce{Sc^3+}$ ion to that of $\ce{Sc^2+}$ it is plain ...
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How to derive the number of spectral lines?

Recently, I found that when electrons in an atomic sample de-excite from a higher energy level ($n_2$) to a lower energy level ($n_1$), the number of spectral lines observed in the spectrum is $$\frac{...
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Does the Atomic Mass listed for each element on the periodic table reflect the relative abundances of their isotopes on Earth? Or in the Universe? [duplicate]

Somehow, I cannot find a site or book or paper explaining exactly how the average atomic masses for the elements on the periodic table are weighted.... I posted a question either here or on Physics S....
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How is the molar weight of C-12 equal to 12 gram ? Why is "g" not considered while calculating molar weight? [closed]

So, I was just pretty confused about how we simply multiply the "mass" of total nucleons in Carbon by the Avogadro Constant, to get the molar "weight" as 12 grams, shouldn't it be ...
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How is most probable radius in quantum mechanical model equal to Bohr's radius in hydrogen atom

Most probable radius in 1s orbital for hydrogen electron is $\pu{0.529E-10 m}$ which is Bohr radius. But energy of electron in hydrogen atom is proportional to mean radial distance in atom. In this ...
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what does it mean to say oxygen in a given context?

My textbook "chemistry by Julia" says the following When it comes to expressing the molar mass of elements such as oxygen and hydrogen, we have to be careful to specify what form of the ...
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What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? [closed]

What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? Would it get ionized or is there no probability of such a thing happening ?
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Why are electrons filled in fourth shell before the third shell is filled?

I am a beginner and am learning about atomic structure and I am getting confusions regarding the aufbau principle. It is said that the electrons will be filled first in lowest available energy level. ...
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If an atom had 200 protons, how much neutrons would it need to have to be most likely stable and why?

I know there is a specific proton/neutron ratio but i'm unaware if it applies to atoms with 86 protons and beyond.
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Why is atomic mass unit/unified atomic mass defined against Carbon 12?

I have searched the web all over this question and I have not really found an answer to my satisfaction. From my understanding of the topic so far, I understand that reason why concept of unified ...
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When is the n+l rule followed when working with energy of different orbitals?

While going through my book, I came across a problem which gave some options about the order of energy of 3s, 3p and 3d orbitals of hydrogen atom. The correct answer was given as: 3s, 3p and 3d ...
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Atoms vs molecule when talking about the avogadro's number? [duplicate]

By far, my understanding is that a molecule is made up of atoms bonded together. For example, a molecule of water ($\ce{H2O}$) has 2 hydrogen atoms and one oxygen atom. However, when it comes to ...
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Why electrons do not distribute evenly among the atoms in a molecule? [closed]

I was wondering why the state where electrons are evenly (or the closest to being evenly) distributed among the atoms in a molecule is not the lowest energy state? For example, in a water molecule it ...
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Rutherford's Alpha Ray Scattering Experiment & Plum-Pudding Model

My teacher said, "Rutherford thought that all the Alpha particles would directly go through the gold foil without any collision if the plum pudding model was right. Because, as said in plum ...
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1 answer
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Schrodinger's Equation and Wave Function

So I understand that there exists the shrodinger's equation, which on solving,gives the wave function of an electron. The wave function as I understand, gives all possible information about an ...
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Is this bond Ionic or Covalent, and why? AlBr [closed]

We know a compound could form between NaCl because they are +1 and -1 ions which make them both into a complete valence set. Could a compound form between Al and Br, for example, and what type of bond ...
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Does the electron in a neutral hydrogen atom ever exist in the p, d or f sublevels?

I learned that the electron in a neutral hydrogen atom can be excited to higher levels. But there are different sublevels in the levels. For example s, p, d and f. Does the electron only jump from s ...
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