All currently known chemical elements have a common "home" - the periodic system.However, they are located there as it is necessary, and in a strict order, a certain sequence.One of the main criteria by which classified all the atoms are characteristic.
physical properties of non-metals
position in the periodic
If we consider the system of chemical elements as a whole, it is possible to determine the place of the situation of non-metals as:
- upper right corner.
- above notional boundary diagonal of boron to astatine.
- main subgroups with the group IV-VIII.
obvious that their number is clearly inferior to that of metals.In numerical terms it will be about 25/85.However, this fact does not diminish their significance and importance.At the same physical properties of non-metals are much more varied than those of their "opponents."
Varieties of simple compounds of non-metals
defines several major categories, which include all the known elements considered.The physical properties of simple substances - non-metals - can divide them into:
In this case there is a special group of elements - the noble gases.According to its characteristics, they do not belong to any of the designated categories.
that are such a lot.These include simple substances such as:
- halogens chloro and fluoro;
- white phosphorus;
However, this is possible provided the standard parameters of the environment.The crystal lattice of these representatives - a molecular type of chemical bonds in molecules - covalent nonpolar.Physical properties of this group of non-metals similar.They have:
- ability limitless mixing between them;
- fill the entire volume of the vessel.
Among the listed substances are poisonous two - chlorine and white phosphorus.Very dangerous, suffocating connection.This chlorine - yellow-green gas, phosphorus - white, flammable in air.
oxygen and ozone - good oxidants.The first - a permanent component of the air required for the life of most organisms.The second image after the storm under the action of electrical discharges of lightning in the air oxygen.It has a pleasant smell of freshness.
physical properties of non-metals of this group can be described, giving the characteristic of only one substance - bromine.As soon as it is a liquid at normal conditions, among the representatives of this group of elements.
It is a dark brown liquid, rather heavy, which is a strong poison.Even a pair of bromine can cause complicated, do not heal for a long time, ulcers on the hands.The smell of it is very bad for that item and its name (translated bromos - stench).
By its chemical characteristics Bromo is an oxidizer and a reducing agent for metals to non-metals stronger than himself.
Despite these features, bromide ions must be present in the human body.Without it, there are diseases associated with hormonal disorders.
By the simple substances in this category include most non-metals.It:
- all allotropic modifications of carbon;
- red and black phosphorus;
- a modification of tin.
They all have an atomic lattice, quite hard, but brittle material.Black phosphorus - fat dry to the touch connection.Red is - a paste.
the hardest of all designated substances is a diamond - a kind of carbon.Physical and chemical properties of this group of non-metals are very different as in the table some of them are located far from each other.Hence, the degree of oxidation is reactive, the nature of the compounds - all of these indicators will vary.
interesting non-metal in the solid state is iodine.Its crystals glisten on the cut, thus showing similarity with metals.It is not surprising, because it is located almost on the border with them.Also it has a special property of the substance - sublimation.When heated, iodine goes into the gaseous state, bypassing the liquid.Couples have its bright, saturated purple color.
physical properties of non-metals: Table
To make it easier to designate what constitutes non-metals, it is best to build a summary table.It will show what are the general physical properties of non-metals, and in what ways they differ.
|physical property||example nonmetal|
|Physical state under normal conditions||Characteristic three: solid (sulfur, carbon, silicon, etc.), gaseous (eg halogens), liquid (bromine)|
|electrical and thermal conductivity||not typical for any purpose other than carbon black and phosphorus|
|Painting simple substance||very diverse.Example: bromine - red, sulfur - yellow, iodine crystals - dark purple, carbon in the form of graphite - dark gray, chlorine - yellow-green, and so on|
|Metallic luster||characteristic only of crystalline iodine|
|malleability and ductility||completely absent.All solids - fragile than some forms of diamond and silicon|
obvious that the physical properties of non-metals are more prevalent differences rather than similarities.If the metals are several characteristics that would fall under each of them, then we have examined the elements is impossible.