Advice 1: How to determine the metals in the periodic table

Sometimes a person needs to accurately indicate the metals in the periodic Table. As the man who practically owns the chemistry, can determine whether a particular element of metal?
How to determine the metals in the periodic table
You will need
  • - the range;
  • pencil;
  • - The Periodic Table.
Take the periodic table, and with a ruler draw a line that starts in the cell with the element Be (Beryllium), and ends in a cage with the element At (Astatine).
The items that will be on the left of this line are metals. And the "below and to the left" is the element, the more pronounced metallic properties it has. It is easy to verify that in the periodic table so metal is France (Fr) is the most active alkali metal.
Accordingly, those elements which are right of the line, have properties of nonmetals. And here, too, a similar rule applies: the more "up and to the right" of the line is the element, the more powerful it is nonmetal. The element in the periodic table is fluorine (F), the strongest oxidizer. He is so active that the early chemists gave him a respectful, though unofficial, nickname: "All razrezami".
There may be questions like "But what about those items that are on the line or very close to it?". Or, for example, "the"top" of the line are chrome, manganese, vanadium. Is it a nonmetal? After all, they are used in the production of steel as alloying additives. But we know that even small impurities of non-metals make the alloy fragile." The fact that the elements located on the line (for example, beryllium, aluminum, titanium, germanium, niobium, antimony) are amphoteric, that is, a dual nature.
As for example, vanadium, chromium, manganese, are the properties of their compounds depends on the oxidation state are the atoms of these elements. For example, such higher oxides like V2O5, CrO3, Mn2O7, have pronounced acidic properties. That is why they are the seemingly "illogical" places in the periodic table. In pure form these elements, of course, are the metals and have the properties of metals.

Advice 2: How to learn the periodic table

For students study table of Mendeleev - a nightmare. Even thirty-six elements that are usually asked by teachers, turn into hours of grueling frustration and headache. Many do not even believe that to learn table periodic really. But the use of mnemonics can greatly facilitate the life of the scholars.
How to learn the periodic table
To understand the theory and to choose the desired techniserve to facilitate memorization of the material, called a mnemonic. Their main trick is the creation of associative relationships, when abstract information is packaged into a vivid picture, sound or even smell. There are several mnemonic techniques. For example, you can write a story from the elements of memorized information, look for consonant words (rubidium - switch, cesium - Julius Caesar), to include spatial imagination, or simply to rhyme the elements of the periodic table.
Ballad of asterimova the elements of the periodic table better with the meaning, according to certain criteria: valence, for example. Thus, alkali metals are very easy to rhyme and sound like song: "Lithium, potassium, sodium, rubidium, cesium France". "Magnesium, calcium, zinc and barium - their valence equal to the pair" - the classics never get old-school folklore. On the same theme: "Sodium, potassium, silver, univalent good" and "Sodium, potassium and Argentum — forever monovalent". Creativity in contrast to cramming, which is enough high for a couple of days, stimulates long-term memory. And so more tales about aluminium, poems about nitrogen and songs about valence and memory go like clockwork.
Acid thrillers facilitate memorization come up with a story in which the elements of the periodic table transformed into heroes, landscape details or story elements. For example, a well-known text: "Aziat (Nitrogen) was pouring (Lithium) water (Hydrogen)in the pine forest (Bor). But he (Neon) we needed, and Magnolia (Magnesium)". It is possible to add story of Ferrari (iron - ferrum), which drove the secret agent "Chlorine zero seventeen" (17 - ordinal chlorine) to catch a serial killer Arseniy (arsenic - Arsenicum), who had 33 teeth (33 - serial number of arsenic), but suddenly something sour hit him in the mouth (oxygen), it was eight poisoned bullets (8 - ordinal position of the oxygen)... can Continue indefinitely. By the way, the novel, written explanation of the periodic table, you can attach the teacher of literature as an experimental text. She will surely enjoy.
To build a Palace, plateto one of the names is quite an effective technique of memorizing, when you turn on spatial thinking. The secret is that we all can easily describe their room or the path from home to shop, school, University. In order to remember the sequence of items you need to place them on the road (or in the room), and to represent each element very clearly, visibly, perceptibly. Here the hydrogen - skinny blond with a long face. Hard worker who lays tile - silicon. A group of aristocrats in an expensive car - inert gases. And, of course, the seller balloons - helium.
No need to force yourself to remember the information on the cards. It is best to associate each element with a certain vivid way. Silicon - Silicon valley. Lithium - lithium batteries in the mobile phone. Options can be set. But the combination of the visual image, the mechanical memory, the tactile sensation of the rough, or, conversely, a smooth glossy cards will help you to easily pick up the smallest details from the depths of memory.
Useful advice
You can draw the same cards with information about elements, as was at one time in Mendeleev, but only to Supplement them with modern information: number of electrons on the outer level, for example. All you have to do is put them to sleep.

Advice 3: How to read the periodic table

The discovery of the periodic law and creation of an ordered system of chemical elements D. I. Mendeleyev became the apogee of the development of chemistry in the nineteenth century. Scientists have been compiled and systematized extensive material knowledge about the properties of elements.
How to read the periodic table
In the XIX century there were no ideas about the structure of the atom. The opening of D. I. Mendeleev was only a generalization of experimental facts, but their physical meaning has long remained unclear. When the first data on the structure of the nucleus and the distribution of electrons in atoms, it is possible to look at the periodic law and the system elements in new ways. Table of D. I. Mendeleev makes it possible to visually trace the periodicity of properties of elements found in nature.
Each element in the table is assigned a specific sequence number (H - 1, Li - 2, Be - 3, etc.). This number corresponds to the charge of the nucleus (number of protons in the nucleus) and the number of electrons rotating around the nucleus. The number of protons, therefore, equal to the number of electrons, and this suggests that under normal conditions, the atom is electrically neutral.
The division into seven periods is happening to the energy levels of the atom. The atoms of the first period have a single-level electronic shell, the second duplex, and the third a three-tier, etc. When filling a new energy level starts a new period.
The first elements of every period are characterized by atoms with one electron at the outer level, are atoms of alkali metals. The period ends with the atoms of noble gases have completely filled outer electron energy level: in the first period, noble gases have 2 electrons in the next - 8. It is because of the similar structure of the electron shells of the group of elements have similar physical and chemical properties.
In the table of D. I. Mendeleev present 8 major subgroups. Such a number is due to the maximum possible number of electrons on the energy level.
At the bottom of the periodic system selected lanthanides and actinides as a separate series.
Using the periodic table you can observe the periodicity of the following properties of the elements: the radius of the atom, the volume of the atom; ionization potential; the strength of the affinity with the electron; the electronegativity of the atom; oxidation; physical properties of potential compounds.
For example, the radii of atoms, when viewed along a period decreases from left to right; grow downwards, if you look along the band.
A clear periodicity arrangement of elements in the table Mendeleyev rationally owing to the continuous nature of the filling of electron energy levels.

Advice 4: How many elements in the periodic table

The periodic law is the basis of modern chemistry and to explain the patterns of change of properties of chemical elements, was discovered by D. I. Mendeleev in 1869. The physical meaning of this law is revealed in the study of the complex structure of the atom.
How many elements in the periodic table
In the XIX century it was believed that atomic mass is the main characteristic of the element, therefore for the classification of substances used it. Now the atoms and identificeret determine the magnitude of the charge of their nuclei (protons and ordinal position in the periodic table). However, atomic mass of elements with some exceptions (for example, atomic mass of potassium is less than the atomic weight of argon) is increased in proportion to their nuclear charge.

With increasing atomic mass and observed periodic variation of properties of elements and their compounds. This metallicity and nemetallicheskie of atoms, atomic radius and volume, ionization potential, electron affinity, electronegativity, oxidation States, physical properties of compounds (boiling point, melting point, density), their basicity, or acidity afternote.

How many elements in the modern periodic table

The periodic table graphically expresses which he discovered the periodic law. In the modern periodic table contains 112 chemical elements (last – Materi, Darmstadt, Rentgene and Copernici). According to recent reports, opened and the next 8 elements (up to 120, inclusive), but not all of them got their names, and these elements are still few publications are present.
Each item occupies a cell in the periodic table and has a sequence number corresponding to the charge of the nucleus of its atom.

How to build a periodic system

The structure of the periodic system represented by seven periods, with ten rows and eight groups. Each period starts with alkali metal and ends with noble gas. The exception is the first period starts with hydrogen, and a seventh incomplete period.

The periods are divided into small and large. Small periods (first, second, third) consists of a single horizontal row large (four, five, six) – two horizontal rows. The upper rows in the larger periods are called even, lower – odd.

In the sixth period of the table after lanthanum (number 57) there are 14 elements, similar properties for lanthanum, the lanthanides. They are made in the lower part of the table separately. The same applies to the actinides, after actinium (#89) and largely repeating its properties.
Even-numbered rows of large periods (4, 6, 8, 10) is filled just metals.

Elements in groups show the same higher valence in oxides and other compounds, and this value corresponds to the group number. Main groups contain elements of small and large periods, the side – just big. Top to bottom the metallic properties are intensified, non – weakened. All the atoms of the side sub-groups – metals.

Advice 5: The history of the discovery of the periodic table

The periodic table of chemical elements has become one of the most important events in the history of science and brought its Creator, Russian scientist Dmitry Mendeleev, the world. This extraordinary man managed to unite into a single concept all the chemical elements, but how he managed to open his famous table?
The history of the discovery of the periodic table

History of the periodic table

By the mid-19th century, scientists were able to access sixty-three chemical element, but to build them in a coherent logical chain does not work. The elements had to be placed in order of increasing atomic mass and divide by similarity of chemical properties in groups.

For the first time his theory similar to the theory of periodic future, proposed by the musician and the chemist John Alexander Newland – however, the scientific community ignored his achievement. Offer Nulend not taken seriously because of his search for harmony and connection between music and chemistry.

Dmitri Mendeleev first published his periodic table in 1869 in the journal of the Russian chemical society. Also, a scientist sent notice of his discovery to all the world's leading chemists, after which he was repeatedly improved and modified the table, until it became what it is know today. What discovery Dmitri Mendeleev was periodic, and non-monotonic change of chemical properties of elements with increasing atomic mass. The final unification of theory in the periodic law occurred in 1871.

The legend of Mendeleev

The most common legend is the opening of the table of Mendeleyev in a dream. The scientist himself has repeatedly ridiculed this myth, claiming that he invented the table for many years. According to another legend Dmitri Mendeleev invented vodka – it came after the defense scientists of the thesis "Reasoning about the connection of alcohol with water".

Mendeleev is still considered by many to be the discoverer of vodka, which he loved to do under the water-alcohol solution. The contemporaries of the scientist often laughed at the laboratory of Mendeleev, which he has equipped in the hollow of a giant oak.

Private jokes was rumored to be the passion of Dmitri Mendeleev by the weaving bags, which scientist did, living in Simferopol. In the future, he with his own hands was making containers of cardboard for the needs of the laboratory, for which he sarcastically called a master of suitcase cases.

Periodic table, except for the ordering of chemical elements in a single system, made it possible to predict the discovery of many new elements. However, at the same time, some of them scientists consider to be non-existent because they were incompatible with the concept of the periodic law. The most famous story at the time was the discovery of such new elements as koroni and ônebuliumö.
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