If for example, an atom had nine electrons, the first two orbit very close to the nucleus, the next seven orbit a little farther away. The outer seven electrons are less tightly held than the inner two electrons because they are further away from the positively charged nucleus. If this atom gets close to another atom, with a loosely held electron in its outer shell, a new orbital will become available to the loosely held electron. This new electron orbital is bound to both atomic nuclei and has a lower energy level than the original electron orbital. The electron can spontaneously jump to it and emit a photon with the excess energy. Now we have an electron orbiting both atoms which results in the atom that provided the electron having a small net positive charge and the other atom having a small net negative charge. The two atoms are now held together by the electromagnetic force of attraction between positive and negative charges. This is called a covalent bond. To break this bond needs the same amount of energy as was released when it was formed.
A water molecule consists of one oxygen atom and two hydrogen atoms held together by a covalent bond. In this case the oxygen atom shares one electron with each hydrogen atom. This means that the oxygen atoms has a small net positive charge and the hydrogen atom has a small net negative charge. As a result, the oxygen and hydrogen atoms are attracted to each other due to the electromagnetic force. Because of this the water molecule is a polar molecule: its charge is not evenly distributed.
Atomic orbitals (except for s orbitals) make different types of covalent bonds:
Covalent bonds are weaker than ionic bonds, and have a lower melting point. They are also generally poor conductors of electricity and heat.
In chemistry, bond length is the measure of the size of a covalent bond. Because molecules are very small, they are measured in picometers, or about one millionth of a billionth of a meter.
The chemistry of molecules is explained mostly by their bonds, and their bonds are caused by their structure of electrons.
Bond
Uses of bond, bonds, bonded, and bonding:
Ionic bond
An ionic bond is the electrostatic forces of attraction between a non-metal and a metal ion in a giant ionic crystal lattice. This occurs when charged atoms (ions) attract. This happens after a metal atom loses one or more of its electrons to the non-metal atom. The greater the difference in charge between the metal and non-metal ion, the stronger the ionic bond. A maximum of three electrons can be transferred in the process.
A metal atom becomes a positive cation because it loses electron(s). A non-metal atom becomes a negative anion as it gains electron(s). This occurs, for example, when sodium and chlorine join to form common table salt, NaCl. First, sodium atoms (Na) oxidize and lose an electron to form positively charged sodium ions (Na). Chlorine atoms gain the electrons from the sodium atoms to form negatively charged chloride ions (Cl). Both ions are now oppositely charged and they are held by strong electrostatic forces of attraction.
Chloride
Chloride is an ion of chlorine. It occurs when chlorine gets reduced, gaining an electrons and becoming an ion. Chloride is necessary for life. It is normally found in the salt sodium chloride, which is very common in diets.
Bauhaus
The Bauhaus was a design school that operated from 1919 to 1933 in Germany. It is widely regarded as the most influential art school of the 20th century. It promoted modernism. It is most well known for teaching painting, photography, advertising, weaving, architecture and the design of furniture and household products. The work that it produced and its teaching methods had a world-wide influence on art, design, photography, architecture and art education.
It was formally called the "Staatliches Bauhaus" from 1919 to 1932 because it was state funded in that period. From 1919 to 1925 it was in Weimar, in the state of Thuringia and from 1926 to 1932 it was in Dessau, in the state of Sachsen-Anhalt. It operated as privately funded school in Berlin from the end of 1932 until April 1933.
Its staff included some of the most famous artists and architects of the 20th century, including: Walter Gropius, who founded the school, Ludwig Mies van der Rohe, Wassily Kandinsky, Lyonel Feininger, Paul Klee, László Moholy-Nagy, Marcel Breuer, Josef Albers, Anni Albers, Oskar Schlemmer and Hannes Meyer.
Its former buildings in Weimar and Dessau were jointly made a UNESCO World Heritage Site in 1996.
Intelligence
Intelligence refers to certain mental powers. There is no general agreement on which mental powers are intelligent or part of intelligence. The idea comes from a Latin word: "intelligo" meaning to "choose between different options". A part of intelligence allows people to solve problems. These problems may be easy to solve. They may also be difficult to solve, and involve abstract thought. For some, intelligence is a property, or characteristic of the mind. For others, it is simply the working of the brain, especially the cerebral cortex.
If an answer is found to a problem, it can be remembered. That way, the problem is solved more quickly when it comes up again. This is what is called learning.
There is disagreement about which has more influence on intelligence, genetics or environment. Also, intelligent behaviour is possibly learned when an organism (a living thing) reacts enough to a stimulus.
Scientists believe that intelligence can be measured or tested. A type of intelligence test would be solving many problems in a very short time. Most of the problems have to do with seeing things, or telling what a rotated shape would look like. Some are also related to mathematics: for example to tell what number would come next in a row. Other tests have to do with words or the understanding of language. After giving such a test to a person, a number would be calculated to give an approximation of the Intelligence Quotient (IQ).
Computer engineers try to build machines that act as if they were intelligent. This is related to computer science and is called Artificial intelligence (man-made "intelligence"). Artificial intelligence uses logic, and often combines it with machine learning. This means that similar to living organisms, the machine has to be trained to solve a problem. After training, it will solve the problem faster.
Intelligence is not limited to humans. Many animals also show signs of intelligence: Animals also need to solve problems, and remembering how a problem is solved is useful to them. Many animals use tools to solve problems. These animals include the Great Apes, dogs, dolphins, elephants, rats and mice, and some birds. All these animals are vertebrates, but tool use isn't limited to these: Even cephalopods and arthropods show signs of intelligence. To be able to compare the behaviours of different species, scientists need to adapt the notion of intelligence.
It has been argued that plants should also be classified as intelligent: They are able to sense and model external and internal environments and adjust their morphology, physiology and phenotype accordingly to ensure self-preservation and reproduction. A counter argument is that intelligence is commonly understood to involve the creation and use of persistent memories.