Trends which are observed in the properties of elements as you move along the periodic table in a given direction.
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26 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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2answers
100 views
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 ...
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2answers
66 views
Did Mendeleev predict the existence of neutrinos?
According to this Wikipedia page, Mendeleev originally believed that the inert gases belonged in Group 0 (to the left of the alkali metals). Thus, helium would be placed in the second period to the ...
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1answer
48 views
Why are elements on the right side of the periodic table nonmetallic and gas at room temperature?
Elements on the left side of the periodic table tend to be solid and metallic, elements on the right side of the periodic table are nonmetal and tend to be gases at room temperature, and the ...
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1answer
43 views
Why does the melting point get lower going down the Alkali Metal Group with increase in atomic number?
Why does the melting point get lower going down the Alkali Metal Group with increase in atomic number?
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0answers
44 views
Reconciling multiple inorganic properties for the purposes of learning these elements
How can I reconcile all of the chemical properties, physical properties and peculiar behaviour of metals in inorganic chemistry for the purposes of studying these systematically?
It is very hard to ...
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1answer
65 views
Solubility of Calcium Fluoride in water
$\ce{CaF2}$ is insoluble in water, but $\ce{CaCl2}$, $\ce{CaBr2}$, $\ce{CaI2}$ are soluble. Why is this so?
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3answers
144 views
Hydrogen - its place in the Periodic Table
Why do some people say that hydrogen should be above lithium in the periodic table and others argue it should be above fluorine?
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1answer
437 views
What is charge density?
For example, Magnesium has a higher charge density compared to Sodium, therefore its metallic lattice is stronger and it has a higher melting point. Does that mean that Magnesium has more protons and ...
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1answer
65 views
Brittle d-block metal trend
I remember seeing a periodic table that had the top-left corner of the d-block shaded and marked as "brittle". If I recall correctly, the elements were $\ce{Sc,Ti,V,Cr,Mn,Y,Zr,Nb,La}$. I think (Sorry, ...
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1answer
160 views
Why are there two Hydrogen atoms on some periodic tables?
Most periodic tables only feature one Hydrogen atom, on the top of the first group. But some, like the one I was given, also show Hydrogen in the 7th group, to left of Helium.
Why are there two ...
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2answers
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Why do atoms generally become smaller as one moves left to right across a period?
It seems to me that the addition of electrons and protons as you move across a period would cause an atom to become larger. However, I'm told it gets smaller. Why is this?
