In term 1, I started my chemistry journey by knowing what is a periodic table. A periodic table is a table that consist of all known elements in the world and are arranged according to their energy level. I was supposed to design cards for the first 20 elements in the periodic table and I took almost 6 hours to just get 20 cards done! It was such a tedious job that I have to work on from afternoon till night time! For each card, I have to list element's atomic number, name and atomic mass. Then, I have to determine the number of protons, neutrons and electrons in each element. Lastly, I need to create a Bohr diagram and Lewis structure of the elements! When I looked at those instructions, I have totally no idea what all those was about and I needed to go online and check about them.
Although it may be a tedious task, but at least I get to know more about the arrangements of the different atoms before moving on to know more about how the periodic table works. Periodic table is 1 amazing work done by the chemists as this is a very special table. It incorporates every part of the links between the different elements.
In a periodic table, elements are arranged in order of increasing proton (atomic) number and are classified according to groups and periods. Group refers to a vertical set of elements while a period is a horizontal row of elements. Elements in the same group have similar chemical properties and will undergo the same type of chemical reactions. Such examples are Lithium, sodium and Potassium, all lies under group I of the periodic table. As you move across a period, the properties of the elements will change gradually from metallic to non-metallic elements. Taking period 1 as an example, the starting element is Lithium followed by Beryllium, Boron, Carbon, Nitrogen, Oxygen and Fluorine. There are in total 8 groups that we learn in secondary 1 in the periodic table. They are named in roman number and they represent a certain type of elements in the group. Like group I would be alkali metals and group II will be Alkaline earth metal. In between group II and III, they are the transition metals which we will learn more about them in secondary 3. Periods in the periodic table can help us determine how much of a shell is occupied with electrons. For example, elements in the period 1 will only have their 1st shell occupied/partially occupied with electrons while element in the period 2 will have the 1st shell fully occupied with electrons and their 2nd shell partially/fully occupied with electrons. Now, I will touch on more about the electronic structure in a periodic table, it is also known as the electronic configuration of an element. Knowing this information can identify almost everything about the element. For example, the configuration of an element is 2.6. We know that there are 2 shells being occupied since there is only 2 digits. The last digit in the configuration could tell us which group it is in and also the valence electron of it. Thus, we know that this element falls in group 6, has 8 electrons and has 2 shells, 1 fully occupied and 1 partially occupied. Therefore, this element would be Oxygen!
Next, I will talk more about valence electron. Valence electron is the one that determines the stability of an element. Valence electron is the ones left over that did not manage to fill up a shell. They will either be given off to another element or taken in to complete the shell or shared among elements. Such process is called chemical bonding. There are 3 types of chemical bonding. They are ionic bonding, covalent bonding and metallic bonding.
Ionic bonding is usually formed between metals and non-metals. Ionic bonding is the electrostatic force of attraction between oppositely charged ions in an ionic compound. Using the formation of sodium chloride (Figure 1) as an example, the sodium atom loses one electron to form a positive ion (cation) in order to obtain an octetstructure. The chlorine atom gains the electron from sodium atom to form a negative ion (anion) in order to obtain an octet structure. The ions have opposite charges and therefore attract each other to form an ionic compound known as sodium chloride. This attraction force is called ionic bond.
An ionic bonding between sodium and chlorine
For covalent bonding, elements share their electrons with each other in order to obtain the electronic configuration of a noble gas. Normally, covalent bonds are formed between atoms of non-metal. Covalent bonds can be formed between atoms of same elements or between atoms of different elements. Compounds which contain covalent bonds are known as covalent compounds. Also, there are 3 covalent bonds. Single covalent bond - One pair of shared electrons between two atoms Double covalent bond - Two pair of shared electrons between two atoms Triple covalent bond - Three pair of shared electrons between two atoms
For example, each oxygen atom requires two more electrons. Instead of sharing a pair of electrons, two oxygen atoms can share two pairs of electrons to form a double bond and obtain an octet structure.
A covalent bond between oxygen atoms
After learning such extraordinary stuffs in term 1, I got really interested in chemistry as there are so many interesting things and crazy stuffs that could be discovered in everyday lives. It is also an easy subject to pick up as everything goes on with logic. I really love chemistry a lot and I think I could do well in term 1 test! :D
These are my cards :D
Although it may be a tedious task, but at least I get to know more about the arrangements of the different atoms before moving on to know more about how the periodic table works. Periodic table is 1 amazing work done by the chemists as this is a very special table. It incorporates every part of the links between the different elements.
In a periodic table, elements are arranged in order of increasing proton (atomic) number and are classified according to groups and periods. Group refers to a vertical set of elements while a period is a horizontal row of elements. Elements in the same group have similar chemical properties and will undergo the same type of chemical reactions. Such examples are Lithium, sodium and Potassium, all lies under group I of the periodic table. As you move across a period, the properties of the elements will change gradually from metallic to non-metallic elements. Taking period 1 as an example, the starting element is Lithium followed by Beryllium, Boron, Carbon, Nitrogen, Oxygen and Fluorine. There are in total 8 groups that we learn in secondary 1 in the periodic table. They are named in roman number and they represent a certain type of elements in the group. Like group I would be alkali metals and group II will be Alkaline earth metal. In between group II and III, they are the transition metals which we will learn more about them in secondary 3. Periods in the periodic table can help us determine how much of a shell is occupied with electrons. For example, elements in the period 1 will only have their 1st shell occupied/partially occupied with electrons while element in the period 2 will have the 1st shell fully occupied with electrons and their 2nd shell partially/fully occupied with electrons. Now, I will touch on more about the electronic structure in a periodic table, it is also known as the electronic configuration of an element. Knowing this information can identify almost everything about the element. For example, the configuration of an element is 2.6. We know that there are 2 shells being occupied since there is only 2 digits. The last digit in the configuration could tell us which group it is in and also the valence electron of it. Thus, we know that this element falls in group 6, has 8 electrons and has 2 shells, 1 fully occupied and 1 partially occupied. Therefore, this element would be Oxygen!
Next, I will talk more about valence electron. Valence electron is the one that determines the stability of an element. Valence electron is the ones left over that did not manage to fill up a shell. They will either be given off to another element or taken in to complete the shell or shared among elements. Such process is called chemical bonding. There are 3 types of chemical bonding. They are ionic bonding, covalent bonding and metallic bonding.
Ionic bonding is usually formed between metals and non-metals. Ionic bonding is the electrostatic force of attraction between oppositely charged ions in an ionic compound.
Using the formation of sodium chloride (Figure 1) as an example, the sodium atom loses one electron to form a positive ion (cation) in order to obtain an octet structure. The chlorine atom gains the electron from sodium atom to form a negative ion (anion) in order to obtain an octet structure. The ions have opposite charges and therefore attract each other to form an ionic compound known as sodium chloride. This attraction force is called ionic bond.
An ionic bonding between sodium and chlorine
For covalent bonding, elements share their electrons with each other in order to obtain the electronic configuration of a noble gas. Normally, covalent bonds are formed between atoms of non-metal. Covalent bonds can be formed between atoms of same elements or between atoms of different elements. Compounds which contain covalent bonds are known as covalent compounds. Also, there are 3 covalent bonds.
Single covalent bond - One pair of shared electrons between two atoms
Double covalent bond - Two pair of shared electrons between two atoms
Triple covalent bond - Three pair of shared electrons between two atoms
For example, each oxygen atom requires two more electrons. Instead of sharing a pair of electrons, two oxygen atoms can share two pairs of electrons to form a double bond and obtain an octet structure.
A covalent bond between oxygen atoms
After learning such extraordinary stuffs in term 1, I got really interested in chemistry as there are so many interesting things and crazy stuffs that could be discovered in everyday lives. It is also an easy subject to pick up as everything goes on with logic. I really love chemistry a lot and I think I could do well in term 1 test! :D