Elements, Compounds & Mixtures

IBYXO - Every object in nature has its own form ranging from solid, liquid, and gas, but this object is not formed without natural classification.

The surrounding objects are formed due to the existence of elements, compounds, and mixtures. This time we will discuss some information about elements, compounds, and mixtures, here is the explanation.

A. Elements

Elements consist of metals and non-metals. Pure substances have properties that distinguish them from other substances. For example, the element hydrogen is composed only of hydrogen atoms. The element oxygen is only composed of oxygen atoms only. The properties of oxygen and hydrogen do not appear in substances formed from both, for example water (H₂O). 

In nature there are 92 types of natural elements, while the rest are artificial elements. The total number of elements in nature is approximately 106 types of elements. Elements are grouped into three (3) parts, namely:

1. Metallic elements

In general, metal elements have shiny white properties, have a low melting point, can conduct electric current, can be forged and can conduct heat or heat. In general, metals are solids, but there is one metal element that is liquid, namely mercury. Some metal elements that are useful in everyday life include:

a. Chrome (Cr)

Used for car bumpers, and mixed with steel to become stainless steel.

b. Iron (Fe)

Is the cheapest metal, as a mixture with carbon produces steel for building construction, cars and railroads.

c. Nickel (Ni)

Solid nickel is very resistant to air and water at ordinary temperatures, therefore nickel is used as a protective layer by gilding.

d. Copper (Cu)

Copper is widely used in electrical wiring, jewelry, and coins. A mixture of copper with tin produces bronze while a mixture of copper with zinc produces brass.

e. Zinc (Zn)

Zinc can be used as roofing, household appliances, and iron coatings to prevent rust.

f. Platinum (Pt)

Platinum is used in car exhausts, electrical contacts, and in the medical field as a safety for broken bones.

g. Gold (Au)

Gold is a highly non-reactive metal, and is found in pure form. Gold is used as jewelry and high-quality electrical components. A mixture of gold with silver is widely used as a coin material.

2. Non-metallic elements

In general, non-metallic elements have non-glossy properties, poor conductors of electric current, and are not malleable. In general, non-metals are poor conductors of heat, but there is one non-metal element that can conduct heat well, namely graphite. Some non-metallic elements that are useful in everyday life, among others:

a. Fluorine (F)

Fluoride compounds mixed with toothpaste function to strengthen teeth, freon - 12 as a refrigerator and air conditioner coolant.

b. Brom (Br)

Bromine compounds are used as nerve tranquilizers, photographic films, and fire extinguisher mixtures.

c. Iodine (I)

Iodine compounds are used as wound antiseptics, additional iodine in table salt, and as a test material for amylum (carbohydrates) in the flour industry.

3. Semi-metallic elements (Metaloid)

Semi-metallic elements have properties between metals and non-metals. Some semi-metallic elements that are useful in everyday life, among others: 

a. Silicon (Si)

Found in nature the second most after oxygen, which is 28% of the earth's crust. Silicon compounds are widely used in cutting and sanding equipment, for semi-conductors, as well as materials for making glass and ceramics.

b. Germanium (Ge)

The existence of germanium in nature is very little, obtained from coal and concentrated zinc rock. Germanium is a semiconductor material, which at low temperatures functions as an insulator while at high temperatures as a conductor.

B. Compounds

Compounds have different properties from their constituent elements. For example, two hydrogen atoms with one oxygen atom can combine to form a water molecule (H2O). Hydrogen is a very light and flammable gas, while oxygen is a gas found in the air that our bodies need for combustion. It is clear that the properties of water are different from those of hydrogen and oxygen Another example of a compound is table salt (NaC1). Table salt is made up of the element sodium and the element chlorine. Sodium has the properties of a light metal, while chlorine is a poisonous gas. The two elements are combined to form table salt in the form of minerals that are needed by our bodies. 

Compounds include a single substance composed of several elements with a fixed mass ratio. In nature there are approximately 10 million compounds. Water (H2O) is the most abundant compound in nature.

Compounds are written in the form of chemical formulas. A chemical formula is a substance consisting of a collection of elemental symbols with a certain composition. The composition is in the form of a number that states the number of constituent atoms (index number). For example, a compound consists of sodium element atoms (Na) and chlorine element atoms (C1). If the index number of each element atom is 1 and 1, then the chemical formula of the compound formed is as follows:

Na index number = 1, C1 index number = 1, so the chemical formula of the compound is NaC1 (Sodium chloride).

Chemical formulas can be molecular formulas and empirical formulas. The molecular formula is a chemical formula that states the type and number of atoms that make up the substance. For example, C2H4, (ethene), H2O (water). Empirical formula is a chemical formula that states the smallest ratio of the number of atoms forming the compound. For example, the chemical formula C2H4, then the empirical formula of the compound is CH2.

C. Mixtures

In everyday life we encounter many mixtures. For example, river water, soil, air, food, drinks, salt solution, sugar solution, etc. The original nature of the substances forming the mixture can still be distinguished from each other, some are indistinguishable. In the air are mixed several elements in the form of gases, including: nitrogen, oxygen, carbon dioxide and other gases. The fresh air we breathe contains more oxygen than polluted air. The air is also composed of several compounds, including: smoke and dust.

Mixtures are grouped into two parts, namely: 

1. Homogeneous Mixture 

A mixture of two or more substances whose constituent particles can no longer be distinguished is called a homogeneous mixture. Homogeneous mixtures are often called solutions. Examples of homogeneous mixtures, among others: a mixture of water with sugar called a sugar solution, a mixture of water with salt called a salt solution. The particle size in solution has a diameter of about 0.000000001 m, and cannot be seen with a microscope. 

Some examples of homogeneous mixtures above are mixtures between liquids. Is there a mixture between metals, so that a homogeneous mixture is formed? There is a mixture of metals with other metals to form a homogeneous mixture. For example, stainless steel is widely used for medical and household appliances. Stainless steel is a mixture of iron, chrome, and nickel.

2. Heterogeneous Mixture 

A mixture of two or more substances whose constituent particles can still be distinguished from each other is called a heterogeneous mixture. 

Examples of heterogeneous mixtures: soil, river water, food, drinks, sea water, cake batter, cast concrete batter, etc. 

In heterogeneous mixtures, the boundary wall between substances can still be seen, for example, a mixture of water and oil, a mixture of iron and sand, a mixture of iron powder and water, etc. 

In heterogeneous mixtures are grouped into two parts, namely: 

a. Colloids 

The particles in colloids can only be seen with an ultra microscope. Particle size between 0.5 m s.d 1 mm. Examples of colloids: milk, smoke, fog, agar-agar. 

b. Suspension 

Particles in suspension can only be seen with an ordinary microscope. Particle size between greater than 0.3 m. Examples of suspensions: oil with water, cloudy water, and lime water.