Element And Compound

2/15/2022by admin
Gold

Dish 9: 1 compound as in dish 4 and 2 compound as in dish 5. Place the examples of elements, compounds, and mixtures on another table (called Table B) and label them. You may also label the compounds with their specific chemical formula (for example, table salt would be NaCl). With the Students. Divide the class into groups of four students each. Understand the Key Definitions. There are four keywords and definitions to get to grips within this. (i) an element (ii) a compound. An element is a pure substance that cannot be decomposed into simpler substances. Elements are listed in the Periodic Table of the Elements. Each element has a 1 or 2 letter symbol. A compound is a pure substance that can be decomposed into simpler substances. Compounds are made up of two or more elements. When there is no public data on the element in its pure form, price of a compound is used, per mass of element contained. This implicitly puts the value of compounds' other constituents, and the cost of extraction of the element, at zero. For elements for which their radiological properties are important, individual isotopes and isomers are.

Differences in Properties

Elements are distinguished by their name, symbol, atomic number, melting point, boiling point, density and ionization energies. In the Periodic Table, elements are arranged according to their atomic number and they are grouped according to similar chemical properties and are depicted by their symbols.

  • Atomic number – the atomic number is denoted by the letter Z and is the number of protons present in the nucleus of the atom of element. For e.g. carbon has 6 protons in its nucleus and for Carbon, Z = 6. Number of protons is also indicative of electric charge or number of electrons present in the nucleus which determines chemical properties of the element.
  • Atomic Mass – the letter A indicates the atomic mass of the element which is the total number of protons and neutrons in the nucleus of an atom of the element. Isotopes of the same elements differ in their atomic masses.
  • Isotopes – isotopes of an element have the same number of protons in their nucleus but differ in the number of neutrons. Naturally occurring elements have more than one stable isotope. Thus isotopes have similar chemical properties (due to same number of protons) but different nuclear properties (due to different number of neutrons). For e.g. carbon has three isotopes, Carbon - 12, Carbon -13 and Carbon - 14.
  • Allotropes – atoms of an element can form bonds with each other in more than one way leading to difference in their chemical properties. For e.g. carbon binds in a tetrahedron to form diamond and layers of hexagons of carbon forms graphite.

Compounds are composed of different elements in a fixed proportion. For example, 1 atom of sodium (Na) combines with 1 atom of chlorine (Cl) to form one molecule of sodium chloride (NaCl) compound.The elements in a compound do not always retain their original properties and cannot be separated by physical means. The combining of elements is facilitated by their valency. Valency is defined as the number of hydrogen atoms required that can combine with an atom of the element forming the compound. Most compounds can exist as solids (low enough temperatures) and can be decomposed by the application of heat. Sometimes foreign elements are trapped inside crystal structure of compounds giving them a non homogeneous structure. Compounds are depicted by their chemical formula which follows the Hill system wherein carbon atoms are listed first, followed by hydrogen atoms after which elements are listed in alphabetical order.

Visualizing the Differences

This picture shows the differences between elements and compounds at an atomic level. Elements have only 1 type of atoms; compounds have more than 1. Elements and compounds are both substances; they differ from mixtures where different substances mix together but not via atomic bonds.

A visualization for the differences between elements, compounds and mixtures, both homogenous and heterogenous.

History of Elements and Compounds

Elements were initially used as a reference to any state of matter like liquid, gas, air, solid etc. Indian, Japanese and Greek traditions refer to five elements namely, air, water, earth, fire and aether. Aristotle conceptualized a new fifth element called 'quintessence' - which apparently formed the heavens. As research continued, many eminent scientists paved way for the current understanding and description of elements. Among them, work of Robert Boyle, Antoine Lavoisier, Dmitri Mendeleev are particularly notable. Lavoisier was the first to make a list of chemical elements and Mendeleev was the first to arrange elements according to their atomic number in the Periodic Table. The most current definition of an element is awarded by the studies carried out by Henry Moseley which states that the atomic number of an atom is expressed physically by its nuclear charge.

Before the 1800s the usage of term compound could also mean a mixture. It was in the 19th century that meaning of a compound could be distinguished from a mixture. Alchemists like Joseph Louis Proust, Dalton and Berthollet and their studies on various compounds have given modern chemistry the current definition of compound. Proust’s work demonstrated to the world of chemistry that compounds were made constant composition of respective elements.

CAS Number

Every chemical substance is identified by its unique numerical identifier – the CAS (chemical abstracts service) number. Hence every chemical compound and element has a CAS number. This makes database searches for elements and compounds more convenient.

Element and compound venn diagram

References

There are several compounds we all use in our daily life, which have become an essential part of our growth and survival. We encounter these compounds in our daily life; in the food we eat, the water we drink and the air we breathe.

A compound is a substance which results from the combination of two or more chemical elements held together by a strong force between them.” Let’s check some compounds that we use in our everyday life.”

1. Water

Chemical Formula: H2O

Almost no living thing can survive without water. Water is everywhere on our planet. It is the reason we have an organic life on earth. A water molecule consists of one oxygen atom combined with two hydrogen atoms. We use water throughout our day and night; in drinking, cooking, household needs, industries, and agriculture. Apart from these general uses of water, you might be amazed to know that water plays a major role in volcanic eruptions. Besides many horrific tales about volcanic eruptions, they are, in fact, very beneficial for us; as they provide nutrients to the surroundings which contain valuable minerals that are beneficial to plants. Therefore, water is the most important compound in our life.

2. Table Salt

Chemical Formula: NaCl

We can find salt on almost every dining table, as the basic ingredient which can be used in so many smart ways other than seasoning your food and is also considered as one of the most effective preservatives. Despite all common household uses of salt, it is also used as a deicing agent. It lowers the freezing point of water and prevents it from freezing. Table salt is a chemical compound made by one atom of sodium and one atom of chlorine, held together by an ionic bond. Almost 96-99% content of table salt is NaCl, rest 1-4% are impurities or other chemical compounds added to it.

3. Sucrose (Sugar)

Chemical Formula: C12H22O11

Sucrose is the common sugar which again forms the major ingredient in baking and cooking. Apart from enjoying sucrose through various desserts and beverages, they are extensively used in pharmaceutical industries, where they act as an additive in medicinal drugs (which taste utterly terrible) to make them more palatable. Sucrose is produced naturally in plants, from where the table sugar is refined. It consists of 12 atoms of carbon, 22 atoms of hydrogen and 11 atoms of oxygen held together by a glycosidic bond.

4. Soaps

Chemical Formula: RCOONa, Where R is a long chain of carbon atoms ranging from 16-18 in number.

We all start our daily routine after taking a good bath. Apart from these normal toilet soaps, there are also some bar soaps containing glycerine, which may help people with dermatological problems like eczema. Soap is the complex and an ionic compound which consists of a long chain of carbons, oxygen and sodium ions held together by ionic bonds.

5. Toothpaste

Chemical Formula: CaCO3 or NaF

Brushing our teeth is first thought come to our mind after we wake up. We have a variety of toothpaste available in the market; like an anti-cavity, extra whitening, for sensitivity and many more. Toothpaste doesn’t only make your teeth white, it may also be used in multiple pays such as; to eliminate show scuff and cleaning containers like thermoses and baby bottles. It is a basic compound which reduces the bacteria present in our mouth.

6. Baking Powder

Chemical Formula: NaHCO3 (Sodium-bi-carbonate ion)

Baking powder is the compound consisting of sodium, hydrogen, and carbonate ions. It is used in baking cakes and desserts. It is also used in neutralizing stomach acidity. Moreover, it can be used as a natural deodorant.

7. Mouthwash

Chemical Formula: H2O2 (Hydrogen peroxide)

Element And Compound

Mouth wash is an antiseptic solution which is used to reduce the antibacterial load in our oral cavity. Hydrogen Peroxide is used to kill bacteria, soothes bleeding gums, sore throat and as a teeth whitener. Along with these uses, it is widely used in industries such as electronic industry where it is used as an oxidizing and cleaning agent in the manufacturing process of semiconductors and printed circuit boards.

8. Nailpaint Remover

Compound

Chemical Formula: CH3COCH3 (Acetone)

Element And Compound Gold

Nailpaint remover is a widely used cosmetic found on the dressing table of most of the women. It breaks down nail polish, making it easy to remove with a cotton swab or cloth. It is widely used because it can easily mix with water and evaporates quickly in the air. Acetone not only removes nail polish but is also helpful in removing gum, oil, and other sticky substances from raw textiles like cotton or silk. Its chemical name is acetone or propane-ol and is a colorless liquid.

9. Vinegar

Chemical Formula: CH3COOH (Ethanoic Acid/Acetic Acid)

Vinegar is the chemical compound consisting, carboxylic acid. It is widely used as a preservative and for seasoning food and salad. It is also used for cleaning purposes. Those beauty conscious people may also find this chemical helpful as it is also used in a pedicure.

10. Alcohol

Chemical Formula: CH3CH2OH (Ethanol)

Alcohol is an addictive psychoactive drug, widely used amongst adults and teenagers to get high. Ethanol is the clear colorless liquid which is widely used in the manufacturing of beer, whiskey, wines and so on.. It is also used as an antiseptic in medical wipes and hand sanitizers.

Element And Compound Reaction

11. Aspirin

Chemical Formula: C9H8O4 (Acetylsalicylic acid)

Element And Compound Table

Aspirin is one of the most common medicines we have heard since childhood. It is used to treat pain, fever, and inflammations. Acetylsalicylic acid is the major component of aspirin and many other medicines.

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