why does an atom gain or lose electron?

Answer 1

it wont loose by its own...
u have to give the energy to give or taken...(engergy means..light,heat,chemical.....etc)
on its own it is gaining and loosing means..that is radio active..ok

Answer 2

an atom never gains nor loses an electron any more than I gain or lose money. I know where my money is -- so I've never lost it. It's in the bank or in someone else's pocket. I never gain any money -- well because I keep answering these questions with thought-provoking answers that lead nowhere.

But seriously an atom may gain an electron if doing so would be energetically advantageous; lose an electron if doing so would be energetically-advantageous. I always tell my students to think about the POLEs -- that is "Positions Of Least Energy". Every system of charged particles will do its best to find the POLEs at which point the energy of the system will be minimized.

So, if an atom would be in a lower energy state with an electron added, then it will gain an electron (if such an electron is available). If an atom would be a lower energy state if it gave up an electron, it will lose an electron (if such a loss is possible).

It's all about the POLEs.

All these jazzy answers from quantum mechanics, shell-filling and valencies are just trinkets to put a bunch of ideas in your pocket. Get to the nitty gritty basic idea of energy conservation and minimization and you have someone who understand science.

Answer 3

I'd like to presume that you know what a valence electron is, but just to make sure, here's a crash course: Electrons orbit the nucleus of the atom. They have a negative charge, while the nucleus has a positive charge. Since they have opposite charges, they attract each other. This attraction keeps the electron in orbit, just like the Earth's orbit around the Sun.

Valence electrons are the electrons in the outer-most orbit, meaning the attraction between them and the nucleus is very weak. If atom A has 1-3 valence electrons and it meets atom B which has 4 or more valence electrons, the tendency of the valence electrons in atom A is to transfer to atom B. Why? Since valence electrons have negative charges, they attract each other. And since there are more electrons in the atom B than in atom A, the electrons in atom B stay put and the valence electrons in atom A are pulled into atom B. Again, just like the Earth and the Sun: the Sun is larger so it stays put, and the Earth is smaller so it's the one that moves around.

Answer 4

An atom gains or loses electron to be stable. An atom has certain configuration that makes it more stable than its original configuaration. This is the reason why some atoms have the tendency to lose and others to gain electrons. Generally, atoms become stable when they gain the configuration of noble gases. To attain this, atoms either lose or gain electrons.

Answer 5

The electron was the first subatomic particle discovered. It was identified in 1897 by the British physicist J.J. Thomson during investigations of cathode rays.

Under ordinary conditions, electrons are bound to the positively charged nuclei of atoms by the attraction between opposite electric charges. In a neutral atom the number of electrons is identical to the number of positive charges on the nucleus. Any atom, however, may have more or fewer electrons than positive charges and thus be negatively or positively charged as a whole; these charged atoms are known as ions. Not all electrons are associated with atoms. Some occur in a free state with ions in the form of matter known as plasma.

Although an atom is normally electrically neutral, it can lose or gain a few electrons in some chemical reactions or in a collision with an electron or another atom. This gain or loss of electrons produces an electrically charged atom called an ion. An atom that loses electrons becomes a positive ion, and an atom that gains electrons becomes a negative ion. The gain or loss of electrons is called ionisation. Any process that can add or remove electrons from an atom or a molecule can produce ions. Radiation and chemical reactions are such processes.

Radiation can increase the energy of the electrons in an atom or a group of atoms. If this energy is increased enough, one or more electrons can overcome the attraction of the nucleus and escape from the atom. The loss of negative charge results in the atom becoming a positive ion. Radiation that can produce ions includes light, X rays, gamma rays, atomic nuclei, subnuclear particles, and electrons. Ionisation, in general, occurs whenever sufficiently energetic charged particles or radiant energy travel through gases, liquids, or solids. Charged particles, such as alpha particles and electrons from radioactive materials, cause extensive ionisation along their paths.

In chemistry, ionization often occurs in a liquid solution. For example, neutral molecules of hydrogen chloride gas, HCl, react with similarly polar water molecules, H2O, to produce positive hydronium ions, H3O+, and negative chloride ions, Cl-; at the surface of a piece of metallic zinc in contact with an acidic solution, zinc atoms, Zn, lose electrons to hydrogen ions and become colourless zinc ions, Zn2+. Ionization by collision occurs in gases at low pressures when an electric current is passed through them. If the electrons constituting the current have sufficient energy (the ionization energy is different for each substance), they force other electrons out of the neutral gas molecules, producing ion pairs that individually consist of the resultant positive ion and detached negative electron. Negative ions are also formed as some of the electrons attach themselves to neutral gas molecules. Gases may also be ionised by intermolecular collisions at high temperatures.

Answer 6

one way of loosing the electron is by gaining the energy from the photon. chemical reactions are good examples of gaining or loosing the electrons. some atoms are having all the orbit fully saturated as per the Hound's law (2n^2). but many atoms' outer most orbit does not posses enough electron to satisfy the hounds law. this is represented by its valances. atom always tries to achieve the stable form and during this course either it looses it electron or gain electron to make its outer most orbit saturated and try to satisfy the hound's law.

Answer 7

It gains or loses an electron in order to become stable and have a full set of valence electrons. The goal of all atoms is to become stable like the noble gases.

Answer 8

the atom has to keep its shell half filled or completely filled according to Hund's rule.the formula is 2n^2 for evry orbital to has its answers.due to the stability in the environment,the atom has to lose or gain electron or electrons.
or due to formation of bond such as covalent bond,ionic bond,electrovalent bond with other atoms so as to form simple or complex compounds,it has to lose or gain electrons,so tht the energy level changes happens(According to Bohr's postulates).
for example,while sodium while in the neutral state,i has 11 electrons,but while fusion with another anionic atom,it loses an electron to cholride which gains an electron to get the covalent bond.
or as.....to get the complete valence shell structure.

Answer 9

1. to become stable
2. to share or exchange electrons for the reason of bonding.
3. Because it was bored and ran out of the daily quota on yahoo answers.

Answer 10

To stablize essentially. If has less than 8, it will strive to gain electrons to become "complete" so to speak.

Answer 11

To gain stability.