Chapter Elements of Chemistry

More than 100 chemical elements that are already known and identified. Each element has characteristics. These elements generally exist in nature, although there are some elements that are artificial. A small part of the element was found in the form of free elements, like for example argon, oxygen, nitrogen, and sulfur.

Understanding Chemical Elements

“Chemical elements is an atomic species that has the same amount of protons in its nucleus”

Available 118 elements that have been identified, 94 of which occur naturally on earth. While 24 the rest of it, is a synthetic element. There is 80 element having at least one stable isotope and 38 the element is a radionuclide which, over time, decays into other elements.

Iron is the most abundant constituent element of the earth based on mass, while oxygen is the most abundant element in the earth's crust.

Chemical elements make up ordinary matter in the universe. However, astronomical observations suggest that the ordinary material that is observed composes 15% from matter in the universe, the rest is dark matter, composition is unknown, But it's not made up of chemicals.

Following are the properties of the elements in the group of elements.

Gas Mulia

The VIIIA class element consists of

helium (He)
neon (Born)
argon (With)
krypton (kr)
xenon (Car)
radon (Rn)

It is called noble gas because at room temperature it is a gas and has very stable or difficult to react properties. Because it is stable, in nature the noble gases are found in monatomic or single atomic form.

Elements of noble gas have low melting point and low boiling point. The boiling point is a few degrees Celsius above the melting point. The melting and boiling points increase from He to Rn. All elements of noble gas, except radon, can be found in the air in the atmosphere.

Halogen

Halogens are elements of the VIIA group that are made up of :

fluorine (F)
chlorine (Cl)
bromine (Br)
iodine (I)
astatin (At).

Nama “halogen” comes from Greek which means salt forming, because the halogen element is able to react with metal elements to form salt compounds. In nature, halogen elements are found in the molecular form of diatomic element F2, Cl2, Br2, and I2.

The melting and boiling points of the halogen increase with increasing atomic number. At room temperature, fluorine and chlorine have some form of gas, Bromine is a highly volatile liquid substance, while iodine has a form that is easy to absorb. All halogens are pungent and poisonous.

Halogens are the most reactive group of non-metallic elements. Halogen oxidation power from F2 to I2 decreases and vice versa, reduction power of halide ions from F− to I− is increasing. Because of that, halogens that are higher up in the periodic system are able to oxidize the halides underneath, but not the other way around.

Metal Alkali

Alkali metal is an element of IA class except hydrogen (H), among others viz :

lithium (At the)
sodium (On)
potassium (K)
rubidium (Rb)
Sesia (Cs)
fransium (Fr)

Called alkali because it can react with water to form hydroxide compounds that are alkaline / based. Alkali metal is the most reactive metal group, until it is always found in nature in the form of its compounds. Alkali metal compounds are usually easily soluble in water.

Alkali metals have soft, light, and has a relatively low melting and boiling point. Alkali metal elements can be identified by a flame test where each element will give a distinctive color

Metal Alkali Soil

Soil alkaline metals are a class IIA constituent composed of :

beryllium (Be
magnesium (Mg)
calcium (That)
stronsium (Sr)
barium (Ba)
radium (Out).

Alkaline earth metals are also able to react with water to form bases, However, it is weaker than alkali metal. Soil alkaline metals also belong to reactive metals, but their reactivity is low compared to alkali metals per se.

other than that, Alkaline metal compounds are usually difficult to dissolve in water and are found underground or in rocks in the Earth's crust.

Elements of the Third Period

The third period elements consist of metals (magnesium, sodium, and aluminum), metaloid (silicone), and non-metals (phosphorus, sulfur, chlorine, and argon).

The nature of the elements of the third period

The tendency of the nature of the third period elements from left to right, that is:

1. Atomic fingers decrease
2. Ionization energy increases
3. Electricity is increasing
4. Metal properties decrease but nonmetallic properties increase
5. The oxidation power increases but the reducing power decreases
6. The melting point rises gradually from Na to Si and then drops dramatically
7. Molecular structure
8. On, Mg, Al: metal crystals; And: giant covalent molecule; P4, S8: molecule polyatom; Cl2: diatomic molecules; and Ar: monoatomik.
9. Acidic properties increase, alkaline decreases

Fourth Period Transition Elements

The fourth period transition elements consist of :

scandium (Sc)
titanium (You)
vanadium (V)
chromium (Cr)
mangan (Mn)
iron (Fe)
cobalt (Co)
nickel (Ni)
copper (With)
seng (Zn).

All of these elements are metal elements which are reductant with relatively high melting and boiling points. other than that, transition elements generally have several oxidation numbers and are able to form complex ions and complex compounds.

Generally the elements of the fourth period transition in nature exist in the form of their compounds, except copper in the form of free elements and their compounds. Transition elements and their compounds are generally able to function as catalysts for chemical reactions in the body of living things or also in industry. The compounds of the transition elements are usually colored, except compounds from Sc3 +, Ti4 +, and Zn2 +.

Such is the language of elemental chemistry, May be useful

Another article :

• Redox and Electrochemical Reactions : Definition and Examples of Questions
• Colligative Properties of Solution : Molaritas, Molality and Mole Fraction
• Geometry Series Formulas and Geometry Series Problem Examples

 

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