The chemical properties of an atom of an element depends on its electronic configuration.
Ions are formed by loss or gain of electrons by atoms.
<h3>What is electronic configuration of an atom?</h3>
Electronic configuration is the arrangement of electrons around the nucleus of an atom.
- How much an element reacts depends on its electronic configuration.
- Noble gases are the least reactive elements because their outer energy levels are filled with octet electrons. (except He, which is full with 2)
In most chemical reactions, atoms try to have the electron configurations of the noble gases by either losing or gaining electrons.
Most atoms want to become stable.
<h3>What is the octet rule?</h3><h3 />
Octet rule is a concept of chemical bonding theory that is based on the assumption that atoms tend to have either empty valence shells (energy levels) or full valence shells of eight electrons. “8 is octet”
<h3>What are Alkali metals and Halogens?</h3>
Alkali Metals and Halogens are the most Reactive Elements
- As members of Group 1, alkali metals have only one electron in their outermost shell.
- By losing that 1 electron, an alkali metal can get an electron configuration like a noble gas, with eight electrons in its outermost energy level.
1s22s22p63s23p64s1 is the electronic configuration of potassium.
Potassium will lose the 1 electron in the 4th energy level so that its outmost energy level is empty.
Potassium does not gain 7 electrons to become stable instead of losing because the energy associated with losing one electron is less than that needed to gain 7 electrons.
- As members of Group 7, the halogens have seven electrons in their outermost shell.
- By gaining one electron, a halogen can get an electron configuration like a noble gas, with eight electrons in its outermost energy level.
1s22s22p63s23p5 is the electronic configuration of chlorine
Chlorine will gain 1 electron to make its outmost energy level full.
After it losing one electron, potassium has the same electron configuration as chlorine does after it gains one electron.
Both are the same as the noble gas argon 1s22s22p63s23p6
- The atoms of many elements become stable by achieving the electron configuration of a noble gas.
- The electrons in the outermost energy level are called valence electrons.
<h3>What are valence electrons?</h3>
To find out how many valence electrons an atom has, check the shorthand electronic configuration.
Magnesium, Mg, has the shorthand electron configuration: [Ne] 3s2
The outermost energy level is the 3 energy level.
This means that a magnesium atom has two electrons, both in the 3s
orbital.
The shorthand electron configuration for phosphorus, P, is: [Ne] 3s23p3
The outermost energy level is the 3 energy level.
This means that each phosphorus atom has five valence electrons: 2 in the 3s
orbital, and 3 in the 3p orbital.
<h3>What are ions?</h3>
- Atoms Gain or Lose electrons to form ions.
- All atoms are different because they have different numbers of protons and electrons.
For example, a potassium atom has 19 protons and 19 electrons .
After losing 1 electron, potassium still has 19 protons but now only has 18 electrons .
Because the numbers are not the same, there is a net positive charge.
An Ion is an atom, radical, or molecule that has lost or gained one or more electrons and has a positive or negative charge.
<h3>The formation of potassium ion</h3>
Potassium atom forms an ion with a 1+ charge in the following step:
K ---> K+ + e-
<h3>What are Cations and Anions?</h3>
- Cation: an ion that has a positive charge.
In the case of chlorine, far less energy is required for an atom to gain one
electron rather than lose its seven valence electrons to become stable.
Show how a chlorine atom forms an ion with a 1- charge:
Cl + e- ----> Cl-
- Anion: an ion that has a negative charge.
Both an atom and its ion have the same number of protons and neutrons so the nuclei are the same.
But, an atom and its ion have different numbers of electrons.
The chemical properties of an atom depend on the number and configuration of its electrons .
So, an atom and its ion have same number atomic number.
Learn more about atoms, ions, and valence electrons at: brainly.com/question/11552489
