Trends which are observed in the properties of elements as you move along the periodic table in a given direction.

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What type of bonding occurs in isolated silicon?

Would isolated silicon engage in network covalent bonding as quartz does or would it engage in a different kind of bonding? Would germanium display similar qualities? *I am asking what is the bonding ...
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Why does ionization energy increase as we go from left to right in a period?

Why does ionization energy increase as we go from left to right in a period? In my textbook, the explanation is as follows: "This is consistent with the idea that electrons added in the same ...
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65 views

Why are inert gas (especially Xenon) compounds powerful oxidizing agents?

I am curious as to why compounds with inert gases, such as $\ce{XeF4}$, $\ce{XeF2}$, and $\ce{XeO3}$ are considered powerful oxidizing agents. I would attribute the phenomenon to the highly oxidized ...
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Why is arsenic more chemically similar to phosphorus than is nitrogen?

Why is arsenic more chemically similar to phosphorus than is nitrogen (to phosphorus)? I thought that it may be because both phosphorus and arsenic have d orbitals (albeit one has one that is filled ...
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29 views

Why is the melting point of TiCl4 lower than TiCl3

I was wondering why the melting point of $\ce{TiCl4}$ was below that of $\ce{TiCl3}$ The melting point of the former is $\ce{-25 Celsius}$ whereas the latter is $\ce{425 Celsius}$ . Thanks!
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102 views

Second ionization potential of Gadolinium

I notice that Gd has a second ionization potential which is significantly higher than would be expected from the general trend in the lanthanides (see this paper p. 945 for a graph). What is the ...
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44 views

Why does the second electron affinity has an opposite sign of the first one?

Most of the first electron affinities are positive, therefore the second ones are negative, and vice versa. but why? SPECIALLY WHEN THE FIRST ELECTRON AFFINITY IS NEGATIVE .. WHY THE SECOND ONE IS ...
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23 views

How adding one more electron increases the ionization energy?

elements of group 6A, compared to 5A, requires less ionization energy due to the paired electrons of 6A but a question arises... why group 7A,compared to group 6A, requires more ionization energy in ...
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100 views

Effect of effective nuclear charge increase on the stabilization of 2s and 2p orbitals

Are 2s or 2p orbitals more stabilized when going from left to right in the period? There are good arguments for both possible answers: 1) 2p orbitals are more stabilized because they penetrate less ...
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How to rationalise the trend in the covalent radii of the transition metals?

Why do the covalent radii of transition series decrease at the start rapidly, then become almost constant and at the end of series begin to increase from left to right in periodic table?
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56 views

Basicity of Group 15 hydrides [duplicate]

Why does the basicity of Group 16 hydrides ($\ce{NH_3,~ PH_3,~ etc}$) decrease down the group ? I know that its Lewis Base nature due to the lone pair but wouldnt the more EN element be less ...
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147 views

Memorizing the periodic table

Several people have said that the key to understanding chemistry is through memorizing the periodic table. I want to ask if there is a simple technique to learn it, or if I just have to remember ...
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37 views

Why is ionization potential considered a periodic property?

Why is ionization potential considered a periodic property??? A periodic property is a one which appears at regular property But we see that every element has some kind of ionization potential
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34 views

How does absence of nd orbital in Oxygen affect its valency?

The original question was 'Oxygen exhibits Oxidation state -2 to +2 but other elements of grp 16 exhibit only +2,+4,+6. Explain Why'. In the solution given i can't understand meaning of this line 'It ...
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134 views

Why do screening effect decreases due to d-orbital?

I am currently learning about p-block elements. In that in 13th group from Boron to Aluminium atomic radii increases. From Aluminium to Gallium atomic radii decreases. From Gallium to Indium atomic ...
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143 views

What is the reason behind choosing the specific elements used for the synthesis of heavier elements?

Attempts to synthesize still undiscovered elements This is derived from the wiki page: "extended periodic table" and is one of the many examples d or f block elements are used in ...
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47 views

Periodic trends: why is effect of protons greater than electrons?

Why is it that adding protons has a greater effect than electron-electron repulsion on periodic trends like atomic radius and ionization energy (assuming # of shells constant)? It seems that if ...
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224 views

Why is Osmium the densest known element

Why is Osmium so dense, Even if we have more heavy elements post to it.
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107 views

Factors of London Forces

In class we learnt that the London forces become stronger as the relative molecular mass increases. Not just as in organic chemistry but in things like the halogens. However, as I understand, the ...
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700 views

Periodic trend in difference of energy between the s and p orbitals

Why does the difference of energy between the 2s and 2p orbitals of the second period elements increase with increasing atomic number? Does this difference increases by moving down a group, e.g. is ...
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159 views

Outermost electronic configuration of f block elements

I have a doubt regarding the general outermost electronic configuration of f block elements. Why is it $(n-2)f^{1-14}(n-1)d^{0-1}ns^2$. The only exception i thought to this formula was thorium ...
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73 views

Can you calculate the properties of a substance based soley on its atomic properties?

I'm trying to write some software that I can use to determine, roughly, what the physical properties of a pure substance are. I know I could just use a database of the known properties of each ...
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340 views

What's the order of oxidising strength of the oxyacids of Chlorine?

What I have been told is that the acidity of the four oxyacids of Chlorine increase in the order $\ce{HOCl} < \ce{HOCl2} < \ce{HOCl3} < \ce{HOCl4}$. I have also been told that the oxidising ...
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311 views

Determining the group number of an element from its successive ionization energies

The successive ionization energies of an unknown element X are: 1st - 9534; 2nd - 11790; 3rd - 13683; 4th - 15309; 5th - 16458. To what group number does X belong? There aren't any significant ...
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92 views

Does there exist any relation between metallic property and oxidation potential?

I was having a revision on periodic table I was thinking about different properties I could connect most of I could not connect metallic property and oxidation potential .
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174 views

Why is the size of Al3+ less than that of Li+?

Why is it so that the size of $\ce{Al^{3+}}$ is lesser than $\ce{Li+}$? I'm a bit confused about this one as the aluminium(III) ion is composed of 10 electrons and 13 protons, while the lithium ...
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Why does bond angle decrease in the order H₂O, H₂S, H₂Se?

I know that bond angle decreases in the order $\ce{H2O}$, $\ce{H2S}$ and $\ce{H2Se}$. I want to know the reason. I think this is because lone pair repulsion but how?
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75 views

Arrange B , Be , Li in order of increasing IE2

IE2 = Second ionization energy the correct arrange of them is like this : Be < B < Li ... But why? Li will have the greatest IE2 because that will involve removing a core electron but what I ...
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605 views

What is the reason for the different solubility of silver halides in ammonia?

According to my knowledge, I know that $\ce{AgCl}$ dissolves in dilute ammonia, $\ce{AgBr}$ dissolves in concentrated ammonia and $\ce{AgI}$ does not dissolve even with concentrated ammonia. What is ...
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92 views

Atomic radii of Sc,Ti and Fe,Co

The atomic radii of Sc is 162pm , Ti is 147pm , Fe is 126pm and that of Co is 125pm. Electronic configuration of Fe is (Ar)3d6 4s2 and that of Co is (Ar) 3d7 4s2. Difference of Z between them is 1 ...
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93 views

How is the oxidation number related to the group number?

How is an oxidation number of an element related to its group? I was trying to answer an homework question.The question was: If an element X forms the highest oxide of the formula XO3, then it ...
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91 views

Calculating Electronegativity of Fluorine [closed]

Calculate the electronegativity of Fluorine from the following data. EH-H = 104.2 kcal/mol EF-F = 36.6 kcal/mol EH-F = 134.6 kcal/mol XH = 2.1 How to solve? Any wiki or link to somewhere where ...
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309 views

Which is more acidic? CO or CO2?

Q1)Which of the given compounds is most acidic? $\ce{CO}$ or $\ce{CO2}$ ? How to solve(explanation)? EDIT: Q2) $\ce{BeO}$ is amphoteric while $\ce{B2O3}$ is acidic - True/False?
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263 views

Ionization Energies of Sulphur and Oxygen Anions

Which of the following are in the correct order of their Ionization Energies?(Multi-Answer Question) a) $\ce{O > S > S- >O-}$ b) $\ce{F > F- > Cl- > Cl}$ c) $\ce{O > O- ...
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379 views

Halogen Oxyacid Trend (acid strength)

Why is $\ce{HClO4}$ more acidic than $\ce{HBrO4}$? But $\ce{HCl}$ is less acidic than $\ce{HBr}$? What determines the acidity? Is it the concentration of $\ce{H+}$? If so, how do these trends develop ...
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248 views

Trends for electrical conductivity?

Which element has the greatest electrical conductivity? (A) As (B) Ge (C) P (D) Sn I am unsure of how to approach this problem. Is there some sort of trend for electrical conductivity or some ...
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270 views

For which pair of species is the difference in radii the greatest?

For which pair of species is the difference in radii the greatest? (A) $\ce{Li}$ and $\ce{F}$ (B) $\ce{Li+}$ and $\ce{F^-}$ (C) $\ce{Li+}$ and $\ce{O^2-}$ (D) $\ce{O^2-}$ ...
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422 views

lanthanide contraction

"The Lanthanide Contraction refers to the fact that the 5s and 5p orbitals penetrate the 4f sub-shell so the 4f orbital is not shielded from the increasing nuclear change." First, 5s and 5p are ...
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Why does sulphur exist as $S_8$ molecule? [duplicate]

Sulphur belongs to the same group as Oxygen. Then why Oxygen exists as an $O_2$ molecule while Sulphur exists as $S_8$ molecule? What's the Chemistry behind it?
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571 views

Why is lanthanum a lanthanide and actinium an actinide?

I do know that the lanthanides start with the element lanthanum, but why? Lanthanum doesn't even have an $f$ orbital, so why isn't it considered a transition metal? It's the same way with actinium, ...
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221 views

Have there been no advances in the determination of effective nuclear charges since Clementi and Raimondi in the 60s?

Effective nuclear charge is a very important concept in chemistry, and is the basis for the qualitative explanation of many observed chemical and physical properties, including several periodic ...
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319 views

What is the joke that is shown in this picture?

There is supposedly a joke shown in this picture relating to periodic trends. Does anyone know what it is? And could they also explain where the elements on the eye exam came from?
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Why does electronegativity increase across a period?

What explains why electronegativity increases as you move across a period? Does it have something to do with the shielding effect of added electrons?
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409 views

Pair of analogous periods on the periodic table

On the periodic table, period 2 and 3, 4 and 5, 6 and 7 and so on have similar blocks, identical length and groups. What are such pairs of analogous periods called?
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Why does chlorine have a higher electron affinity than fluorine?

Since fluorine has its valence electrons in the n=2 energy level, and since chlorine has its valence electrons in the n=3 energy level, one would initially expect that an electron rushing towards ...
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691 views

Which is more metallic?

Which element has more metallic character - aluminium or magnesium? I know that metallic character decreases along a period(from left to right)and increases down a group. Aluminium comes after ...
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286 views

Oxidation state of group 2 elements

I have came across the following statement : "the oxidation state $+II$ is stable for the elements of the alkalin earth metals" , the same is true for the elements of the first group , i've looked for ...
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63 views

Can you determine whether a compound can form given particular elements?

Say you are given a set of particular elements, such as Dy, C, I, Er, P; is it possible to determine whether a compound exists with all of the given elements and no more? If not, is it possible to ...
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906 views

Why is periodicity seen in these certain properties?

I missed my lesson on periodicity so had to teach myself, and have always forgotten to ask my teacher to explain to me why these trends are seen, which, unfortunately, the textbooks don't. Density: ...
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Melting and boiling points of transition elemets

The melting and boiling points of transition elements increases from scandium ($1530^\mathrm{o}\:C$) to vanadium ($1917^\mathrm{o}\:C$). They increase because as we go across the group, we have more ...