ATOMIC ELEMENTS AND ELECTRONS

Electrons as we know are negatively charged particles which revolve round the nucleus of an atom. Elements on the other hand are substances that cannot be broken down by chemical means. We can say that elements are defined by the number of protons they possess because protons do not change. click here to read on atomic structure.

There is a relationship between electrons and its elements i.e. the electrons determine the chemical properties of an element. In this session, we are studying specifically why an element carries a positive charge when it loose an electron and also why an element carries a negative charge when it gains an electron. This question forms a basis of understanding chemistry. We are going to discuss this lesson under two (2) sub-topics;

 WHY AN ATOM CARRIES A POSITIVE CHARGE WHEN IT LOOSES AN ELECTRON
Before discussing this in details, it is imperative to understand that an atom do not gain or lose proton, it can only lose or gain electron. That is why electrons account for chemical properties of an element.

Now, back to our discussion, let’s consider sodium (Na) as an atom. If sodium (Na) loses one (1) electron, the following below are observed;





                                                   FOR SODIUM ATOM (Na)


                                                 Number of electrons = 11


                                                  Number of protons =11


i.e. for sodium atom to be electrically neutral, the number of proton must equal number of electron.


                                                FOR SODIUM ION (Na+)


                                             Number of electrons = 10


                                               Number of protons = 11

electronic configuration of sodium

As observed above, we can see that sodium has lost one electron. The number of electrons (negatively charged particles) is now ten (10) and the number of positively charged particles remains the same i.e. the proton. We can now observe that the number of positively charged particles (proton) is one (1) greater than the number of negatively charged particles, thereby making sodium (Na) atom to carry a positive charge (i.e. a positive 1) as shown by the calculation below;

Charge = number of electrons + number of protons

                        =-10 + 11

                        = +1

WHY AN ATOM CARRIES A NEGATIVE CHARGE WHEN IT GAINS AN ELECTRON

For this outline, we are going to explain direct as we have already given some basic information we need to know about the atom in the previous outline.


Let’s consider chlorine (Cl) in this case. If chlorine atom gains an electron, the following will be observed;



                                                 FOR CHLORINE ATOM


                                            Number of electrons = 17

                                            Number of protons = 17




                                                  FOR CHLORINE ION


                                             Number of electron =18
   
                                             Number of proton = 17

electronic configuration of chlorine 

As observed above, we can see that chlorine atom has gained one (1) electron. The number of electron (negatively charged particles) is now 18 and the number of positively charged particles (proton) remains 17. Therefore the negatively charged particles is one (1) greater than the number of positively charged particles thereby making chlorine atom to carry a negative charge (i.e. a negative 1)  as shown by the calculation below;

                                        Charge = number of electrons + number of protons

                                                        = -18 + 17

                                                        = -1

NOTE: Atom gain or lose electrons in other to attain stability. Also not all atoms that bonds attain the octet configuration.