Hello chemistry brothers and sisters, chemistry greetings, In this post, Kang Ayub will discuss chemical bonds, so before entering into chemical bonding, you must know about electron configuration, why? because chemical bonds will be formed when one atom bonds with other atoms and forms compounds, the atoms undergo changes in such a way that they have electron configurations like the noble gases.
Chemists, do you know that these elements cannot be found in a free state, but in the form of molecules or compounds, because molecules are more stable than elements in a free state.
The atoms of the elements tend to follow the noble gases to achieve stability. it has 2 valence electrons; noble gas elements have 8 valence electrons so noble gases are stable
If an atom tries to have 8 valence electrons, it is said to follow the octet rule. Elements with low atomic numbers (such as H and Li) trying to have 2 valence electrons like He are said to follow the duplet rule.
Do you know how the element tries to achieve stability like a noble gas? Now this element tries to achieve stability by binding to one element with another complementing element, well humans are also like that not yet stable before marriage, after marriage humans are stable by complementing one another.
How Elements Achieve Chemical Bond Stability
a. By removing electrons
This method is usually done by metallic elements that have less than 4 valence electrons. Elements that release their electrons will form positive ions (+).
It can be seen that the number of valence electrons is 1, then the Na element will try to achieve stability by releasing 1 electron to form Na + ions .
It can be seen that the number of valence electrons is 3, then the Al element will try to achieve stability by releasing 3 electrons to form Al 3+ ions .
b. By accepting (capturing) electrons
This method is usually done by non-metallic elements that have more than 4 valence electrons. Elements that accept electrons form negative ions (-).
The number of valence electrons is 6, so to achieve stability like the noble gas elements, the O element must accept (capture) 2 electrons to form the O 2- ion .
The number of valence electrons is 7, so to achieve stability like the noble gas elements, the Br element must accept (capture) 1 electron to form the Br ion –
c. By sharing electrons (covalent bonds)
This method occurs when non-metallic elements combine with each other the number of shared electrons tends to reach the octet and duplet rules.
An ionic bond is an electric attraction between ions with different charges. An ionic bond is formed between an atom that easily loses electrons (metal atoms) and another atom that readily accepts electrons (non-metal atoms).
In the formation of an ionic bond, the number of electrons lost must equal the number of electrons gained. These oppositely charged ions cause attractive forces or strong electrostatic forces so that ionic bonds occur and form compounds that have ionic bonds called ionic compounds .
Also read :
- Polar and Non Polar Covalent Bonds and Their Electronegativity Relationships
- Understanding Chemical Bonds, Ionic Bonds, Ionic Bond Formation
- Understanding Covalent Bonds, Formation and Properties of Covalent Bonds
- 31-40 Chemical Bonding Questions and Discussions
- 16-30 Chemical Bonding Questions and Discussion
- 40 Chemical Bonding Questions and Discussion
- Definition, Formation and Properties of Ionic Bonds and Examples
Generally, ionic bonds occur between metals that tend to lose electrons and non-metal atoms that tend to accept electrons. For example, the bond that occurs between Na atoms and Cl atoms. In achieving stability, the Na atom will release 1 electron to form a positive ion Na + , while the Cl atom will receive 1 electron to form a negative ion Cl – . If Na and Cl bond, both will do the handover or transfer of electrons. Na will give 1 electron to Cl and Cl takes
Example of KCl
In achieving stability, the K atom will lose 1 electron to form a positive ion K + , while the Cl atom will receive 1 electron to form a negative ion Cl – . If K and Cl bond, both will do the handover or transfer of electrons. Na will give 1 electron to Cl and Cl takes
In general, ionic bonds are formed between:
- Positive ions with negative ions.
- Small ionization potential energy atoms with large electron affinity atoms (atoms of group IA, IIA elements with atoms of group VIA, VIIA elements)
- Atoms with a small electronegativity with atoms having a large electronegativity, the difference in electronegativity to form ionic bonds is 1.5
Ionic compounds are generally composed of metallic and nonmetallic elements. Examples of ionic compounds are NaCl, KBr, CaO, AlCl3 , KCl and others. The physical properties of ionic compounds are as follows:
1. The crystal is hard but brittle
When an ionic compound is hit, there will be a shift in the position of the positive and negative ions, from the original alternating to face-to-face. This causes the positive ions to meet face to face with positive ions and a repulsion occurs. This is what causes the crystals of ionic compounds to be brittle. An example is salt
2. Has a high melting point and boiling point
In general, ionic compounds have high melting and boiling points because of the strong electrostatic forces generated between positive and negative ions.
3. Easily soluble in water
When crystals of ionic compounds are put into water, water molecules will infiltrate between positive and negative ions so that the electrostatic attraction of positive and negative ions will weaken, and eventually become brittle.
4. Can conduct electric current
Positive and negative ions when moving can carry an electric charge. If the ionic compound is split into positive ions and negative ions and can move freely, then the ionic compound in the liquid state and the solution can conduct electricity because the ions move freely. However, in the solid state, ionic compounds cannot conduct electricity because the ions cannot move.