K or potassium is the s block alkali metal having monoatomic atom expressed in a single form. We will discuss potassium in detail.
K is the next element of sodium and has almost the same physical property as sodium. Like both are alkali metals and form strong bases with a reaction with water. It appears as a silvery white solid. Its ore name is carnallite KCl.MgCl26H2O.
It found 2.6% of the weight in the earth’s crust. Now we will discuss the basic chemical properties of Potassium with proper explanation in the following article.
1. Potassium symbol
The atomic symbol is that to express an atom by one or two letters and for a molecule, it should be called a molecular symbol. Let us predict the atomic symbol of Potassium.
The atomic symbol of Potassium is “K” as the name start with the English alphabet “P”. but here the name in Latin word is Kalium, so the name starts with “K”. There is also an element in the periodic table has symbol “P” is phosphorus. So, distinguish two elements the symbol of potassium is “K”.
2. Potassium group in the periodic table
A column of the periodic table where the element is placed by the atomic number is called a group. Let us predict the group of Potassium in the periodic table.
The group of Potassium in the periodic table is 1. Because it is an alkali metal itself, it can easily form cations by donating an electron. So, it is placed in the 1st group as an element.
3. Potassium period in the periodic table
The horizontal rows of the periodic table are called a period and correspond to the successive occupation of orbitals of the valence shell. Now predict the period of the Potassium.
Potassium is belonged to period 4 in the periodic table because it has more than 18 electrons in the valence shell so it is placed in the fourth position of the periodic table in the period and also in the group.
4. Potassium block in the periodic table
The block of the periodic table is known as the set of atomic orbitals of an element where the valence electrons are lying. Let us predict the block of the Potassium.
Potassium is an s block element because the valence electrons present in the orbital is s or the outermost orbital of the Potassium is s, so it belongs to s block element like alkali metals. There are only four blocks present in the periodic table, they are s,p,d, and f according to the orbitals.
5. Potassium atomic number
The number of protons present in the nucleus is called the atomic number of that particular element. Let us find the atomic number of the Potassium.
The atomic number of Potassium is 19, which means it has 19 protons and also it has only 19 electrons because we know the number of protons is always equal to the number of electrons and for this reason, they become neutral due to the neutralization of equal and opposite charges.
6. Potassium atomic weight
Atomic weight is the mass of one atom of that particular element of the ratio of some standard value. Let us calculate the atomic weight of Potassium.
The atomic weight of potassium on the 12C scale is 39 which means the weight of Potassium is the 39/12th part of the weight of the carbon element. The original atomic weight of Potassium is 39.0983, it is because the atomic weight is the average weight of all the isotopes of the element.
7. Potassium Electronegativity according to Pauling
According to Pauling electronegativity is defined as the power of an atom in a molecule to attract electrons to itself. Let us predict the electronegativity of Potassium.
The electronegativity of Potassium according to the Pauling scale is 0.82, which means it is more electropositive in nature and can attract electrons towards itself. The most electronegative atom as per the Pauling scale in the periodic table is fluorine having 4.0 electronegativity.
8. Potassium atomic Density
The atomic density is the number of atoms or nuclides per cm3 or in a unit volume of atoms in a material. Let us calculate the atomic density of Potassium.
The atomic density of Potassium is 0.862 g/cm3 which can be calculated the diving the mass of the Potassium by its volume. Atomic density means the number of atoms present per unit volume but the atomic number is the number of electrons present in the valence and inner orbital.
- Density is calculated by the formula, atomic density = atomic mass / atomic volume.
- The atomic mass or weight of the Potassium atom is 39.0983 g
- The volume of the Potassium molecule is 22.4 liter at STP as per Avogardo’s calculation
- So, the atomic density of the Potassium atom is, 39.0983/(2*22.4) = 0.8727g/cm3
9. Potassium melting point
The point where a substance changes its solid state to a liquid or the temperature where the change occurs as atmospheric pressure. Let us find the melting point of the Potassium atom.
The melting point of the Potassium atom is 63.50 C or 336.5K temperature because at room temperature Potassium exists as a solid form where all the atoms in the Potassium lie in an ordered manner due to higher energy, so if we increase the temperature then the elements are placed in good arrangement.
10. Potassium boiling point
The boiling point is where the vapor pressure of the substance becomes equal to the atmospheric pressure. Let us find the boiling point of Potassium.
The boiling point of the Potassium atom is 758.80 C or 1031.8K because it exists in solid form at room temperature so the boiling point of the Potassium atom is also very high even at very high positive temperature.
The van der Waal’s force of attraction is low so high energy of heat is required for the boiling Potassium. The solid form of Potassium exists at room temperature or higher temperature from its melting point.
11. Potassium Van der Waals radius
Van der Waal’s radius is the imaginary measurement between two atoms where they are not bound ionically or covalently. Let us find van der Waal’s radius of Potassium.
The van der Waal’s radius of the Potassium molecule is 280 pm because the value is close to the value of which is proposed by Pauling. Van der Waal’s radius is calculated by the mathematical formula considering the distance between two atoms, where atoms are spheres.
- The formula used the find out the Van der Waal’s radius is, Rv = dA-A / 2
- Where RV is the Van Waal’sal’s radius of the molecule
- dA-A is the summation of the radius of two atomic spheres or the distance between the center of two spheres.
12. Potassium ionic radius
Ionic radius is the summation of the radius of cation and anion respectively, for an ionic molecule in a crystal structure. Let us find out the ionic radius of Potassium.
The ionic radius of Potassium is 280 pm is the same as the covalent radius because for Potassium the cation and anion are the same and it is not an ionic molecule, rather it forms by the covalent interaction between two Potassium atoms.
13. Potassium isotopes
The elements that have same number of protons but different numbers of neutrons of substances are called isotopes of that original element. Let us discuss isotopes of Potassium.
Potassium has three types of proton based on neutron and they are discussed below
- Potassium (39K) – It is the more stable form of Potassium among all other isotopes, having 19 electrons and 19 protons, but it has 20 neutrons and an abundance of 93.3%.
- Potassium (40K) – It is also a stable isotope of Potassium and its abundance is very much lower than 39K, it has 19 electrons, and 19 protons but 21 neutrons. It has a half-life of 1.248 *109 years. It has a nuclear spin of 4 and a relative abundance of 6.7%. 40K is the radioactive isotope of Potassium emitting β particles.
- Potassium (41K) – It is the heaviest isotope of Potassium having very high stability like 39K very little abundance (0.012%) in the atmosphere. It has 19 electrons like others but the number of neutrons is 22.
14. Potassium electronic shell
Electronic shells are those which are surrounding the nucleus and containing a specific number of electrons in it. Let us discuss the electronic shell of Potassium.
The number of electronic shells of Potassium around the nucleus is 6, which is s and p orbitals. Because it has more than 18 electrons and to arrange 18 electrons need 1s,2s,2p, 3s, 3p, and 4s orbital as p orbital contains six electrons and s orbital contains two electrons.
15. Potassium electron configurations
The electronic configuration is an arrangement of the electrons in available orbital by considering Hund’s rule. Let us discuss the electronic configuration of Potassium.
The electronic configuration of Potassium is 1s22s22p63s23p64s1 because it has 19 electrons and those electrons should be placed to the nearest orbital of the nucleus s and p orbitals and for the 1st,2nd, 3rd, 4th orbitals where the principal quantum numbers are 1,2,3, and 4. So, it is denoted as [Ar]4s1.
Here the first number stands for the principle quantum number, the letter is for orbital and the suffix number is the number of electrons.
16. Potassium energy of first ionization
The energy required for the removal of the last valence electrons from the respective orbital is called the first ionization energy. Let us predict the first ionization of Potassium.
The first ionization occurs for Potassium from its s orbital to remove one electron. The energy required for the first ionization of a Potassium atom is 4.34 EV because there is lesser energy required removal of electrons from the 4sorbital which is far away from the nucleus and the force of attraction is low.
Not necessary to remove electrons always for the s orbital, it depends on the valence orbital, if the valence orbital will be p, d or f then the electron is removed from the p, d, and f orbital respectively.
17. Potassium energy of second ionization
Second ionization is the removal of the outermost electron from its +1 oxidation state of the element. Let us see the second ionization of Potassium.
The 2nd ionization energy of Potassium is 40.36 EV because in the 2nd ionization electron is removed from the filled 3p orbital. So, when an electron is removed from a filled orbital then it needs more energy, and also 3p is close to the nucleus than the 4s orbital, so its 2nd ionization is very high than 1st.
After electron removal from electron from the filled 3p then the system will be unstable and energized, so the process is unfavorable, and for this reason, 2nd ionization energy is very high than 1st ionization energy of potassium.
18. Potassium energy of third ionization
Third ionization is the removal of electrons from the respective orbital having a +2 oxidation state of the element. Let us see the third ionization of Potassium.
The third ionization occurs for the potassium from the 3p orbital, and the energy required for this process is 44.20 EV. Because the removal of electrons from the 3p orbital needs more energy than the 4s orbital because it is placed near to nucleus.
19. Potassium oxidation states
The oxidation state is the charge present over the element after the removal of such numbers of an electron to form a stable bond. Let us predict the oxidation state of Potassium.
The stable oxidation state of Potassium is +1 because it has only one electron in the s orbital and when the electron is removed then it can form a stable single bond, so it has +1 oxidation state as the s orbital contains a maximum of two electrons.
20. Potassium CAS number
CAS registry number is a special kind of number a unique unmistakable identifier number provided worldwide. Let us know the CAS number of Potassium.
The CAS number of the Potassium molecule is 7440-09-7, which is given by the chemical abstracts service. Which is different from the CAS number of the other element.
The CAS number of K is unique and not matching with the other element’s CAS number.
21. Potassium Chem Spider ID
The Royal Society of Chemistry gives a particular unique number for every chemical element which is knowns as Chem Spider ID. Let us discuss it for Potassium.
The Chem Spider ID for Potassium is 4575326, which is given by the royal society of chemistry, and by using this number we can evaluate all the chemical data related to the Potassium atom like CAS number it is also different for all elements.
22. Potassium allotropic forms
Having the same chemical but different physical properties of different structural forms of the same element. Let us discuss the allotropic form of Potassium.
There is no allotropic form of potassium is present in the universe, because it does not show catenation properties like carbon.
23. Potassium chemical classification
Chemical classification is the classified the element by its reactive nature, or they cause hazards to the human body. Let us know the chemical classification of Potassium.
Potassium is classified as an alkali metal at room temperature because it can produce heat and electricity also the density of the element is very high and it is more ductile.
24. Potassium state at room temperature
The condition is characterized by the element at room temperature and experimental pressure. Let us predict the state of Potassium at room temperature.
Potassium exists in a solid state at room temperature because it has higher van der Waal’s interaction so the atoms exist very close to each other. The randomness of the atoms is very high at room temperature.
The solid-state of the Potassium can be changed to liquid or solid at a very low temperature, where the randomness will be decreased for the Potassium atom.
25. Is Potassium paramagnetic?
The materials tend to get weakly magnetized in the direction of the magnetizing field when placed in a magnetic field. Let us see whether Potassium is paramagnetic or not.
The Potassium atom is paramagnetic in nature, due to the presence of one unpaired electron in its 4s orbital, after the first ionization K+ is diamagnetic in nature because all the electrons in the 3p orbitals exist as paired up form.
So, we have to check the number of electrons present in the valence orbital for an element whether it is paired form or unpaired form then it will be paramagnetic or diamagnetic accordingly.
Conclusion
K is the s block alkali metal and can react with water by the explosion. K can form different types of oxide, but the superoxide of K is highly observed. Because it has a larger size due to the increase in the principal quantum number so its holding capability also increased that why it can form super oxide.
Hi……I am Biswarup Chandra Dey, I have completed my Master’s in Chemistry from the Central University of Punjab. My area of specialization is Inorganic Chemistry. Chemistry is not all about reading line by line and memorizing, it is a concept to understand in an easy way and here I am sharing with you the concept about chemistry which I learn because knowledge is worth to share it.