Rubidium, a chemical element with a symbol Rb, is one of the highlyreactive alkali metals of group 1 with atomic number 37 in the periodic table. Rubidium is not found in a free state in nature due to its high reactivity behavior so that it is abstracted from different compounds (mostly from salts).

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As we know how much rubidium is being used in the world ofchemistry, so we must have very good proper information about its electronic properties to survive in the world of chemistry and that’s why you are here toknow what valence electrons and valency ofrubidiumare, aren’t you? But for thisyou have to know what these two terms are, so without wasting your time let"s gofor it,

Difference between valence electrons and valency

Valence electrons are the total number of electrons presentin the outermost shell of an atom (i.e. in outermost orbital). The valenceelectrons for a neutral atom is always definite, it cannot be varied (more orless) in any condition for a particular atom and may or not be equal to itsvalency.


Valency is defined as the total number of electrons an atomcan lose, gain, or share at the time of bond formation to get astable electronic configuration i.e. to complete an octet. The valency of an atom canbe variable in different compounds or in chemical reactions due to different bondingmechanisms.

Rubidium (Rb) valence electrons

There are four simple steps to find out the valence electrons forrubidiumatom which are:

Step 1: Find the Atomic Number


To find out the atomic number of rubidium, we can use the periodictable. With the help of the periodic table, we can easily see that the atomic number of rubidiumis 37. As its atomic number is 37, it has a total of 37 protons, and forneutral rubidium, the number of protons is always equal to the number of electronsi.e. 37 electrons in the nucleus.

Step 2: Write Electron Configuration


Electron configuration is the arrangement of electrons on theorbitals. The rubidiumatom has a total of 37 electrons, so we have to put 37 electrons in orbitals. The first two electrons will go in the 1s orbital as Sorbital can hold a maximum of two electrons only. The next two will go in 2sorbital and the next six electrons will go in 2p orbital as P orbital can onlyhold a maximum of 6 electrons and so on...
Now wehave,
Rubidium electron configuration Rb (37) =1s22s2p63s2p6d104s2p65s1(completeconfiguration) or5s1(condensed configuration).

Step 3: Determine Valence Shell

As we know, the valence shell of an atom can be found from the highest number of principle quantum numbers which is expressed in the term of nand in1s22s2p63s2p6d104s2p65s1, the highest value of n is 5 so that the valence shell of Rb is 5s1.

Step 4: Find Valence Electrons

The total number of electrons present in the valence shellof an atom is called valence electrons, and there is only one electron presentin the valence shell ofrubidium(5s1). Thus,rubidiumhas only one valenceelectron.

Valency of Rubidium (Rb)

There are many different ways to find out the valency of anatom which reflects the ability of an atom to bond with other atoms. Valence describeshow easily an atom or a free radical can combine with other chemical species. Thevalency of an atom is determined based on the number of electrons lost, gained, or shared with another atom.

An atom is said to be stable when its outermost shells haveeight electrons (except H and He). If the total number of electrons inoutermost shells is between one to four, the atom has positive valency and ifelectrons are between four to eight, the valency is calculated by subtractingfrom eight and valency is negative. Atoms having four outermost electronspossess both positive and negative valency and atom having eight outermostelectrons have zero valencies (i.e. noble gases).

Alkali metals likerubidiumreached the stable (nearest inertgas configuration) by losing one outermost electron. So that the valency ofrubidium(Rb) is 1.

We can also find the valency ofrubidiumwith the help of a periodic table. Asrubidiumis an element of group 1 which indicated alkalimetals group and valency of alkali metals are always 1.

Valence electrons and valency of Rb+

Rubidium-ion Rb+ means it has lost one electron and has only 36 electrons in the orbitals. The electron configuration of neutral Rb is1s22s2p63s2p6d104s2p65s1but in Rb+ it loses one electron, so it has a new electron configuration of1s22s2p63s2p6d104s2p6means Rb+ has (2+6=8) outermost electrons which makes it stable. Thus,rubidiumion (Rb+) has eight valence electrons.

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Rb+ valency is not zero like noble gas as their outermostshell has eight electrons. when arubidiumatom loses one electron, Rb+ ion is produced and that’s what valency is. So that Rb+ valency is +1 not zero.

Chemical Properties

Rubidium (Rb) atom
Atomic number37
Number of protons37
Number of electrons37
Electron configuration1s22s2p63s2p6d104s2p65s1
Valence electrons1

Rubidium-ion (Rb+)
Number of electrons36
Electronic configuration1s22s2p63s2p6d104s2p6
Valence electrons8