Questions tagged [atomic-radius]
For questions about the atomic radius - a measure of the size of an atom, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding "cloud" of electrons.
135
questions
-2
votes
0
answers
41
views
What is atomic radius? [closed]
I need to understand what the atomic radius means, in the context of periodic properties. I'm not sure, but I think it refers to the radius of an atom, the distance from the nucleus to the last ...
- 25.6k
0
votes
1
answer
170
views
Ionic radii of cations and anions
My textbook mentions that across a period from left to right, the ionic radius of atoms decreases. I'm a bit puzzled because negative ions in the same period have an extra shell. I get the part about ...
- 652
0
votes
1
answer
48
views
Does Cu+ have a greater ionic radius than Sr2+?
Although Strontium is in group 2, reducing the number of electrons as it becomes ionized makes it group 18, period 4 in terms of electrons. Therefore, ionized Strontium (Sr2+) is in the same period as ...
CommunityBot
- 1
0
votes
1
answer
347
views
If the effective nuclear charge of Beryllium(Be) is less than Sodium's(Na), how is the ionization energy of Be higher than Na?
According to Slater's rules the effective nuclear charge of Beryllium and Sodium is 1.95 and 2.20 respectively.
That means that the outermost electron of Na feels a stronger attraction from the ...
- 57k
2
votes
0
answers
161
views
Size of Lanthanum
I was going through the values of atomic and covalent radii of the d-block elements.
The atomic radii of $\ce {Sc},\ce {Y}$ and $\ce {La}$ are $164, 184$ and $187$ pm respectively (Source: Wikipedia). ...
- 59
1
vote
1
answer
2k
views
Compare the covalent character of ZnCl2, CdCl2,HgCl2
I want to know how to arrange the covalent character of ZnCl2, CdCl2, and HgCl2.
By Fajans' rules, We know that a smaller cation equals higher covalent character.
We also know that atomic size ...
1
vote
0
answers
4k
views
Effective nuclear charge on 3p electron of aluminum
Using Slater's rule I calculated the effective nuclear charge on 3p electron of aluminium as:
Config: $\ce{1s^2 (2s^2 2p^6) (3s^2 3p^1)}$
$S = 2(0.35) + 8(0.85) + 2 = 9.5$
$Z_{eff} = Z - S = 3.5$
The ...
- 1
3
votes
4
answers
453
views
Comparison of atomic radii of boron and beryllium
Let me write down a couple of facts and this will be easier for you to know the essence of the question.
Radius of boron is smaller than beryllium.
Ionization energy of boron is smaller than ...
- 9
0
votes
1
answer
751
views
Shielding effect of d electrons
In transition elements shielding effect is observed . Due to this zinc shows abnormality in atomic size.
But at the same time we also say that gallium has same similar size as aluminium due to poor ...
CommunityBot
- 1
-3
votes
2
answers
130
views
Why does atomic radius decrease across periods? [closed]
My textbook says that this happens because the number of protons, and thus the total positive charge, increases - a greater attractive force acts on each electron. The book says that this is despite ...
- 36
0
votes
1
answer
454
views
How does O2- have the largest radius [closed]
Why is the correct option O^2-, aren't all of them equal since they all have the same number of energy shells and same number of electrons in them
- 144
0
votes
2
answers
196
views
Why ionic radius increases with negative charge?
Here's my understanding:
An ion with a negative charge has gained electrons. Hence the negative charge.
With a greater negative charge, there should be more attraction towards the positive charge.
As ...
- 144
1
vote
0
answers
103
views
What role does atomic radius play in the strength of a covalent bond?
How exactly do atomic radii influence the strength of a covalent bond? For instance, if I had a carbon atom covalently bonding to a fictitious nonmetal atom $\ce{X}$ and another nonmetal atom $\ce{Y}$ ...
- 193
4
votes
1
answer
612
views
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 ...
- 408
1
vote
0
answers
25
views
Which ionic radius is most relevant for anticipating co-crystalization?
In the context of anticipating the likeliness that elemental impurities co-crystalize into the crystals containing an element of similar radius (see this question), which is the relevant radii to ...
- 1,097
0
votes
2
answers
312
views
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 ...
- 284
1
vote
1
answer
4k
views
Atomic Radius of Manganese and Chromium
It is clearly a general trend that the atomic radii of the 3d elements in ascending order of atomic weight, leads to the following trend as in the graph below.
But, it was pointed out to me that, Mn ...
- 116
3
votes
2
answers
18k
views
Is there regular decrease in atomic radii of 3d series?
The following fragment of the table of atomic radii from CrystalMaker — Elements, Atomic Radii and the Periodic Table shows a regular decrease in the atomic radius of 3d series:
Table of Atomic Radii
...
- 37.6k
13
votes
1
answer
344
views
Newer ionic radii data than Shannon's 1976 compilation?
Shannon, R. D., 1976, Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides: Acta Crystallographica Section A, v. 32, p. 751–767. DOI: 10.1107/...
- 44k
0
votes
1
answer
397
views
Bohr's postulate of quantisation of angular momentum
The Bohr's postulate of quantisation of angular momentum can be written in a formula as
$mvr = nh/(2π)$
where $m$ is mass of electron
$v$ is its velocity
$r$ is the radius of that shell
$h$ is Plank's ...
- 21.7k
0
votes
0
answers
536
views
Ionic radii of transition metal ions in the presence of weak field and strong field ligands
In the graph given in this image, I was told by my teacher that whenever we start filling the eg orbitals there is an increase in the radius because these orbitals face the ligand directly ...
- 171
1
vote
1
answer
1k
views
Why are hydrated lithium ions' radii larger than hydrated sodium ions' radii?
Why are hydrated lithium ions' radii larger than hydrated sodium ions' radii i.e. $r_\ce{Li+(aq)}>r_\ce{Na+(aq)}$?
If ionic radii increase down the group i.e. $r_\ce{Li+}<r_\ce{Na+}<r_\ce{K+}$...
CommunityBot
- 1
2
votes
1
answer
98
views
Do external electronic shells influence internal ones?
There is a well-known electron shielding effect: negatively-charged internal electronic shell screens external shells from positive nuclei, thus increasing their radii.
Thus, 2S orbital radius of Li ...
- 57k
0
votes
1
answer
6k
views
Comparison between van der Waals radius and metallic radius
I was reading about different types of atomic radius. It was written that if any atom can possess all the three types of radius, then van der Waals radius will be greater than metallic radius. However ...
- 11
3
votes
3
answers
6k
views
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 ...
- 40.2k
0
votes
0
answers
59
views
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 \...
- 318
0
votes
1
answer
147
views
Height of FCC arrangement
I have read that height of HCP arrangement is given by $\mathrm{4r\sqrt{\frac23}}$ as distance between consecutive layers is $\mathrm{2r\sqrt{\frac23}}$(in both FCC and HCP). If that is the case, then ...
- 25.6k
9
votes
2
answers
17k
views
Why the radius of noble gases is more than the halogens or the previous groups?
Noble gases have larger radii than that of halogens.
Sometimes it is greater than the radius of group I elements.
Why is it like that? When we talk about radii of noble gases, what type of radius is ...
- 1,272
5
votes
1
answer
3k
views
Why does magnesium have a greater ionization energy than lithium?
I'm a high school student and I'm learning about ionization energy and atomic radius of elements. I want to compare the ionization energy of lithium and magnesium.
Here is the information provided in ...
3
votes
2
answers
421
views
Why does being "bonded" decrease atomic size?
I have a furiously overwhelming question-
Why is the atomic size of noble gases larger than the atomic size of
the previous halogen when atomic sizes decrease across a period?
I did search it on the ...
- 408
2
votes
1
answer
3k
views
What is the average distance between electron 'shells' in an atom? Or between the innermost shell and the nucleus? [closed]
Somehow, I've never come across any mention of the actual, physical distances between, say the 1s and 2s shells in an atom, whether large or small....
I know that p, d and f (and g?) shells are oddly ...
- 3,091
1
vote
1
answer
1k
views
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 ...
- 1,401
-5
votes
1
answer
99
views
what is the use of finding out the radius of an atom [closed]
I happen to come across this, but what is the radius of an atom, velocity, KE, PE, etc.. actually used for?
like the formula r=0.529n^2/z and so on
- 83
3
votes
1
answer
733
views
Why is strontium(II) ion bigger than krypton atom?
$\ce{Sr^2+}$ is exactly the same as $\ce{Kr}$, in terms of electrons and orbitals.
The only difference between the two, is that $\ce{Sr^2+}$ has a couple of extra protons in the nucleus (and probably ...
- 39
1
vote
0
answers
268
views
Why is the increase in covalent radius from As to Bi not as big as from N to P?
The following is the radius of Group $15$ elements:
$$\begin{array}{c|c} \hline
\text{Element} & \text{Covalent Radius }(\pu{pm}) \\ \hline
\ce{N} &75 \\
\ce{P} &110 \\
\ce{As} &...
0
votes
0
answers
66
views
Why does dissolved oxygen concentration decrease with increasing atomic number of metals?
I am looking at how metal ions ($\ce{Fe^2+}$, $\ce{Ni^2+}$, $\ce{Cu^2+}$, $\ce{Zn^2+}$, and $\ce{Ag+}$) affect the biochemical oxygen demand in water and used the Winkler's method to find out the ...
- 1,379
-2
votes
1
answer
322
views
Distance of subshells from nucleus [closed]
Which subshell is more closer to the nucleus.4f or 6s?
6s gets filled first so does it have to be more closer to the nucleus?
- 41.4k
0
votes
1
answer
76
views
Forcing atoms closer together [closed]
Is there a method in chemistry to alter the energy of atomic bonds by forcing atoms closer together in a smaller volume?
Similar to how pressure squeezes atoms closer together.
- 12.1k
4
votes
1
answer
4k
views
What is the difference between the Bohr model and the quantum model?
Specifically, Bohrs atom model gives the radius of an atom as 0.53Å, while a quantum description offers a similar value. What is the difference between these?
CommunityBot
- 1
4
votes
1
answer
8k
views
Why is the difference between atomic radii of Na and K greater than that of Rb and Cs?
I am aware that this question has already been asked here: Why does the "gap" between atomic radii get smaller down the periodic table?.
However, I was wondering if there is a way to ...
CommunityBot
- 1
2
votes
1
answer
6k
views
Finding orbit radius using the Bohr model and Rydberg equation
To start with its a homework problem, quite lengthy.
A particle of mass equal to 208 times the mass of an electron moves in a circular orbit around a nucleus of charge $+3e$. Assuming the Bohr ...
- 777
5
votes
1
answer
915
views
Covalent atomic radii: oxygen vs nitrogen
Many books state that $R_\ce{N} > R_\ce{O}$ which is in accordance with the general trend. However, some books say that $R_\ce{O} > R_\ce{N}$ because of repulsion caused by pairing of electrons.
...
- 6,238
1
vote
0
answers
33
views
Reason for needing multiple radii for the same atom [duplicate]
Why do we need different types of atomic radii? Why can't there be just one radii for an atom?
- 7,010
2
votes
0
answers
226
views
How to calculate electric force on valence electron?
In order to understand the periodic trends more fully, I wanted to calculate the net force exerted on the electron (with the highest principal quantum number and azimuthal quantum number) of an atom.
...
- 129
1
vote
2
answers
934
views
How to compare size of subshells?
For the same principal quantum number, on increasing the value of the azimuthal quantum number does the average radius of the subshell increase or decrease?
In other words, which out of, say, 3s, 3p, ...
- 12.1k
6
votes
1
answer
2k
views
Why is platinum denser than gold?
The atomic masses of gold and platinum are 196.96657 u and 195.084 u respectively, meaning that (on average) an individual gold atom is heavier than an individual platinum atom.
At the same time, the ...
- 71.1k
0
votes
1
answer
156
views
In the gold foil experiment why didn't thallium form? [closed]
When alpha particles hit the gold nucleus shouldn't they form thallium.
More over shouldn't it also ionize the gold or any atom it hits how does it remain unchanged unionized?
- 8,519
1
vote
0
answers
291
views
Why doesn't core charge increase down a group? [closed]
Atomic radius increases down a group because the electrons feel a lesser attraction to the positive nucleus (due to shielding from inner shells). Why then, doesn't core charge decrease seeing as core ...
- 151
-2
votes
1
answer
33
views
How value of energy of elecron becomes more negative and radius of orbit decreases with increase in the value of atomic number? [closed]
I know how energy of elecron and radius of orbit depends upon principal quantum number......But how it depends upon atomic number?
CommunityBot
- 1
1
vote
0
answers
1k
views
Why is the strontium ion smaller than the potassium ion? [closed]
The ionic radius of the $\ce{Sr^2+}$ ion is $\mathrm{132\,pm}$, while the ionic radius of the $\ce{K^+}$ ion is $\mathrm{152\,pm}$. Why is this the case? I would have thought that since $\ce{K^+}$ has ...
- 19