Some nature of the periodic elements

Periodic properties of elements are properties that change uniformly in accordance with the increase of atomic number elements. Periodic properties of elements associated with the electron structure of elements. Periodic properties of elements including the atomic radius, ionization energy, electron affinity, and electronegativity.

1. Atomic Radius
atomic radius is the distance from the center core to the outermost electron. Atomic radius is determined by measuring the bond length (distance between the nuclei) in covalent compounds, such as the Cl-Cl or H-H and then dividing by two. Therefore, the radius of an atom is often called the covalent radius.
Atomic radius varies depending on the size terikan between nucleus and electrons. The bigger the attraction, the smaller the atomic radius. Factors affecting the attraction of this is the number of protons in the nucleus and the amount of skin that contains the electrons.
Core with a lot of larger numbers of protons have a greater attraction for electrons, including the outermost electron. So, in a period from left to right, the radius of the smaller atoms. When we move from top to bottom in a class of periodic structure, the number of electron shells increases and, therefore, atomic radius increases as well.

2. Ionization Energy
Ionization energy is the minimum energy required to remove one electron from a neutral atom or an ion in the form of gas. Factors influencing the ionization energy, among others, the core charge, the distance from the core electrons, and the number of electrons that is between the outer and core electrons. In one group, atomic radius increases so that the core appeal of the smaller outer electrons, electrons are easily removed, the energy needed to remove more small. From left to right in one period, as described in the previous section, the core attraction of the greater electron, electrons are more difficult to be released, the greater ionization energy. It can be seen in this picture.












3. Electron Affinity
Electron affinity is the energy that accompanies the process of adding one electron on sati in the form of neutral gas atoms to form negative ions.










4. Electronegativity
Electronegativity is a number that states the tendency of an element to attract electrons in a chemical bond side. An atom's electronegativity is its atomic Affected by both weight and the distance That its valence electrons from the charged nucleus reside. The higher the electronegativity associated number, the more the element or compound Towards it attracts electrons.

periodic system: the brief summary

Periodic system shows grouping elements. Attempts to classify the elements has been started since the experts (in the late 18th century) found more and more elements. The simplest grouping is to divide the elements into metals and nonmetals.

In 1829, Johan Wolfgang Dobereiner see any similarities between the nature of some elements, and classify the elements of nature according to similarity. Each group was composed of three elements, so-called Triade. If the elements in one Triade increase ordered by atomic mass, atomic mass and it attributes the second element is the average of the atomic mass / properties first and third elements. Dobereiner findings showed a relationship between atomic mass and properties of elements.

In 1864 a British chemist named AR Newlands announced the discovery of the so-called law of octaves. Newlands arrange the elements according to their relative atomic mass increases. Proved the elements that differ 1 octave (element number 1 to number 8, element number 2 to number 9, and so on) show similarity properties. At Newlands octave compiled list, the elements of noble gases (He, Ne, Ar and so on) has not been found. Newlands octave law only applies to light elements (low Ar)

In 1869 the Russian scholar named Dmitri Ivanovich Mendeleev, based on observations of 63 elements known at that time, concluded that the properties of elements are periodic function of the relative atomic mass. That is, if the elements arranged according to their relative atomic mass increases, the specific properties will be repeated periodically. Mendeleev create the periodic elements of a list drawn up according to their relative atomic mass increases. Elements that have characteristics in common are placed in vertical columns called groups. Mendeleev periodic list published in 1872. There are several weaknesses in the Mendeleev periodic system: first, the placement of some elements not to increase their relative atomic mass. For example, the placement of tellurium (Te) and iodine (I). Heavier tellurium (Ar = 128) preceding the lighter iodine (Ar = 127). This upside-down placement had made considering the similarity in the nature groups elements. Iodine more shows similarities with the nature of fluorine, chlorine and bromine, while tellurium more shows similarities with the nature of oxygen, sulfur and selenium.
second, there are still many unknown elements at the time, so in the table there are many empty places.

In 1914 Henry GJ Moseley discovered that the order of elements in the periodic table according to the increase in atomic number elements. Placement of tellurium and iodine are not in accordance with the relative atomic mass increases, the increase was in accordance with the atomic number. Tellurium has atomic number 52 while the 53 iodine. A periodic nature rather as a function of atomic number.

Modern periodic system, which is also called long-form periodic system, arranged according to the increase in atomic number and similarity of properties. Modern periodic system can be considered as improvements Mendeleev periodic system.

chemistry: element, compound, and mixture

Element is a single substance that can not be chemically broken down into other substances. Some examples of elements are oxygen, nitrogen, hydrogen, buy, gold, silver, and many more. Distinguished element of Logan and non-metals. Some examples of the metal element is iron (Fe), gold (Au), copper (Cu), etc. Some examples of non-metals are oxygen (O), carbon (C), sulfur (S). Elements of a transition from metal to non-metallic character of Logan and also non-metals, metalloids known elements. For example silicon, boron, and arsenic.

The compound is a single substance that can be chemically broken down into two or more substances. Some examples of compounds are water, sucrose, and sodium chloride. Water can be broken down by electricity into hydrogen gas and oxygen gas. Sucrose can be broken down by heating the charcoal (carbon) and water. Sodium chloride can also be described by the electric (electrolysis), the sodium and chlorine. A chemist from the French, namely Joseph Louis Proust (1754-1826) found that the mass ratio of elements in a compound is fixed. For example, the mass ratio of hydrogen with oxygen in water (1: 8), does not depend on the amount of water that were analyzed. This also means that the mass of hydrogen which reacts with oxygen to form water is 1: 8. if hydrogen is not reacted with oxygen in the ratio 1: 8, then one of them will be left.

The mixture is a material formed from 2 or more substances that have the nature of the substance came from. The types of solutions are mixed, suspensions, and colloids. The solution is a homogeneous compound. Each solution consists of a solvent and solute. In solution, the solute dispersed in the form of particles is very small with a diameter of less than 1 nm. Suspension is a heterogeneous mixture consisting of particles - small particles of solid or liquid dispersed in liquid or gas. Particle size greater than 100 nm. is a form of a mixture of two or more substances that are homogeneous but have a dispersed particle size is large enough 1-100nm. Some examples of colloids are milk, fog, jelly etc

material: mass and energy

Chemical study of the matter. The universe can be divided into the material world and the world of energy. Matter into the author all sorts of things. Energy is the ability to conduct business. Energy is the cause of the change of material. Matter has mass and weight. Mass and weight are two different quantities. The mass of an object or material that remains. However, the weight of an object depends on the acceleration of gravity in accordance with the equation:

G = m. g

Where: G = weight
m = mass
g = acceleration due to gravity


every material has the energy. Energy is owned by materu divided into kinetic and potential energy. Kinetic energy is energy possessed by the moving material. Wind, water, and the speeding car has kinetic energy. Energy is owned by a material that is not related to the motion is called potential energy. The relationship of matter and energy expressed by the equation made by Albert Einstein

E = m. c2

Where: E: energy
m: mass
c: speed of light = 3. 10e8 m / sec

meteri properties are distinguished on physical properties and sifar kmia. Material manifestation of being solid, liquid and gas.

chemistry: introduction

Chemistry is the study of material composition, properties, change, and energy that accompanies change. chemistry observe the material from the atomic to molecular scale.

Chemistry, along with mathematics, physics, and biology is a scientific basis for the other branches of science. Various technologies are currently developing an application of chemistry and basic knowledge of others.

Chemistry is divided into several sections of organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, and biochemistry.

Nowdays, Applications of science is highly developed. Medical technology, medicine, agriculture, industry, and much more. All will I write this blog. There are many things I could for here.

introduction

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