Question #a6bde

1 Answer
Dec 11, 2017

An atom is neutral. Atoms become charged when they form ions, such as through chemical reactions.

Explanation:

An atom, by definition, is neutral. It is the simplest "everyday" form of matter. An atom consists of a positively charged nucleus, surrounded by negatively charged electrons in discrete energy levels around the nucleus. The nucleus itself contains positive particles known as protons, and neutral ones known as neutrons.

If an atom has positive and negative stuff, how then can it have no overall charge? This is because the number of protons is the same as the number of electrons in an atom. A proton has a relative charge of +1, and an electron has a relative charge of -1. If the numbers of these are the same, it is clear that there is no overall charge on the atom.

If an atom because charged, it becomes an ion. Ions occur when an there are a different number of protons and electrons. This can form during chemical reactions: in the reaction between magnesium and chlorine to form magnesium chloride, the chlorine forms chloride ions.

#Mg_((s))+Cl_(2(g))->MgCl_(2(s)#

Each chlorine atom, in this case, gains an electron from the outer shell of the magnesium atom, forming 2 negative chloride ions (if you gain negative stuff, you become negative). At the same time, the magnesium loses two electrons, forming a positive ion with a charge of +2.

An atom can also become ionized if hit by some radiation, such as X-Rays. In such a scenario, the energy from the light ray is transferred to the electron of the atom, causing it to leave the atom (in a very simplified explanation). Radiation that does this is called 'ionizing radiation,' and, as you can imagine, if this happens to an atom in your DNA, this could potentially cause some problems, such as cancers.