The Periodic Table VI - The alkali metals. | The Lattice best dish rack
In the previous chapter of this series we talked about one particular atom, hydrogen. Today we speak of a column of the periodic table, the first column, we can call the Group I alkali metals.
They have been known compounds of these elements for many years, but the metals themselves as such, and pure, could not be obtained until electrochemical methods began to emerge. It is quite possible that many of you ye never directly observed none of these metals, I've only had the pleasure of seeing best dish rack live sodium.
Located to the left of all of the periodic table, the first column or the first group, the alkali metal, comprising the first atoms of each period, so that all atoms are present electronic configuration [noble gas] ns, which means noble gas noble gas electron configuration of Z-1 and equal to the period where the metal of which we speak.
Look at your configuration ns: very uncomfortable one electron above a group of electrons best dish rack perfectly placed. Clearly, here spare someone, and if someone has to give away is unclear who will be the electron in the s orbital. Ie has a very low ionization potential.
Put another way, they are all very, very close to being stable ... which means they really are very unstable. But before getting to their chemistry, I speak of physical properties.
All alkali metals are shiny silver best dish rack metals except cesium, which is of a golden color, and francium, well, no one knows what. As good metals are very good electrical and thermal conductors, but the other features make the alarm for anyone who thinks the word metal. They are very soft, softer as we go down the group: the battery can be cut with a knife without much effort, potassium directly and cut like butter. In addition, their melting best dish rack points are low, below lower line is the element we look. To finish best dish rack the matter they are all very, very low density. Lithium is the least "exaggeration" of them all, as discussed below. best dish rack
That the alkali metals are soft and low melting that is explained by its metallic bond, which is rather weak, as in metallic bonds are usually the outer electrons responsible of the link, and we find these metals only one electron per atom. Add a table taken from my notes in which it can compare three characteristics: melting enthalpy atomization and density.
The melting column is illustrative in itself. The enthalpy of atomization (indicated by the triangle and that H hydrogen NO but enthalpy) is the energy that you have to give a specific amount of substance for it to break down into its separate atoms in gaseous form. Simply, the larger, the more stable the substance. It is easy to see that the first two columns are proportional, the higher its enthalpy of atomization, the higher its melting point. The trend in both columns has not a single irregularity.
As the density is not as easy to see why are ordered well, but it makes sense if you think about it, the best way to understand it is to look at a periodic table and see the length of the periods to which belongs each of the metals. For starters you have to give account of what they are sparse, as water has a density of 1 g/cm3, the iron has about 7.87 g/cm3 ... comparad. Lithium is very, very thin (almost half the water!), The sodium is almost double best dish rack the lithium but potassium is less dense than sodium! Why? And then, going from potassium to rubidium density rises again, but this time almost double! Seriously, the next two paragraphs are entirely optional and cost me write his own, if not ... well saltároslos understand, do not be put exams.
Now, it would be normal to assume increasing density as we go down the column, because every time we have more protons and neutrons within the nucleus, but if you remember when I told you about the atomic radius know that it increases the further down we are in the table, and also increased relatively linear without abrupt changes, best dish rack and here is the point of the matter. It turns out that the atomic radius increases each time a bit, but between period and period does not always add the same number of protons. Cómorl?? Let's see: lithium has Z = 3, because the first period has only two atoms, best dish rack sodium is denser because even with increasing atomic radius, in the period of lithium, sodium itself best dish rack off, and no two
In the previous chapter of this series we talked about one particular atom, hydrogen. Today we speak of a column of the periodic table, the first column, we can call the Group I alkali metals.
They have been known compounds of these elements for many years, but the metals themselves as such, and pure, could not be obtained until electrochemical methods began to emerge. It is quite possible that many of you ye never directly observed none of these metals, I've only had the pleasure of seeing best dish rack live sodium.
Located to the left of all of the periodic table, the first column or the first group, the alkali metal, comprising the first atoms of each period, so that all atoms are present electronic configuration [noble gas] ns, which means noble gas noble gas electron configuration of Z-1 and equal to the period where the metal of which we speak.
Look at your configuration ns: very uncomfortable one electron above a group of electrons best dish rack perfectly placed. Clearly, here spare someone, and if someone has to give away is unclear who will be the electron in the s orbital. Ie has a very low ionization potential.
Put another way, they are all very, very close to being stable ... which means they really are very unstable. But before getting to their chemistry, I speak of physical properties.
All alkali metals are shiny silver best dish rack metals except cesium, which is of a golden color, and francium, well, no one knows what. As good metals are very good electrical and thermal conductors, but the other features make the alarm for anyone who thinks the word metal. They are very soft, softer as we go down the group: the battery can be cut with a knife without much effort, potassium directly and cut like butter. In addition, their melting best dish rack points are low, below lower line is the element we look. To finish best dish rack the matter they are all very, very low density. Lithium is the least "exaggeration" of them all, as discussed below. best dish rack
That the alkali metals are soft and low melting that is explained by its metallic bond, which is rather weak, as in metallic bonds are usually the outer electrons responsible of the link, and we find these metals only one electron per atom. Add a table taken from my notes in which it can compare three characteristics: melting enthalpy atomization and density.
The melting column is illustrative in itself. The enthalpy of atomization (indicated by the triangle and that H hydrogen NO but enthalpy) is the energy that you have to give a specific amount of substance for it to break down into its separate atoms in gaseous form. Simply, the larger, the more stable the substance. It is easy to see that the first two columns are proportional, the higher its enthalpy of atomization, the higher its melting point. The trend in both columns has not a single irregularity.
As the density is not as easy to see why are ordered well, but it makes sense if you think about it, the best way to understand it is to look at a periodic table and see the length of the periods to which belongs each of the metals. For starters you have to give account of what they are sparse, as water has a density of 1 g/cm3, the iron has about 7.87 g/cm3 ... comparad. Lithium is very, very thin (almost half the water!), The sodium is almost double best dish rack the lithium but potassium is less dense than sodium! Why? And then, going from potassium to rubidium density rises again, but this time almost double! Seriously, the next two paragraphs are entirely optional and cost me write his own, if not ... well saltároslos understand, do not be put exams.
Now, it would be normal to assume increasing density as we go down the column, because every time we have more protons and neutrons within the nucleus, but if you remember when I told you about the atomic radius know that it increases the further down we are in the table, and also increased relatively linear without abrupt changes, best dish rack and here is the point of the matter. It turns out that the atomic radius increases each time a bit, but between period and period does not always add the same number of protons. Cómorl?? Let's see: lithium has Z = 3, because the first period has only two atoms, best dish rack sodium is denser because even with increasing atomic radius, in the period of lithium, sodium itself best dish rack off, and no two
No comments:
Post a Comment