Some atoms have only a few electrons in their outer shell, while some atoms lack only one or two electrons to have an octet. In cases where an atom has three or fewer valence electrons, the atom may lose those valence electrons quite easily until what remains is a lower shell that contains an octet. Atoms that lose electrons acquire a positive charge as a result because they are left with fewer negatively charged electrons to balance the positive charges of the protons in the nucleus.
Positively charged ions are called cations. Most metals become cations when they make ionic compounds. Some atoms have nearly eight electrons in their valence shell and can gain additional valence electrons until they have an octet. When these atoms gain electrons, they acquire a negative charge because they now possess more electrons than protons.
Negatively charged ions are called anions. Most nonmetals become anions when they make ionic compounds. We can use total electrons or valence electrons to illustrate the electron transfer process between sodium atoms and chlorine atoms.
First, we will look at the arrangement of electrons in sodium. As demonstrated in the previous section, sodium is likely to achieve an octet in its outermost shell by losing its one valence electron.
Now it has the same number of electrons as the nearest noble gas, neon. Because the ion has 11 positive protons and 10 negative electrons, there is a net positive charge. That charge is shown as a superscript at the top, right of the symbol.
The third shell of the ion is empty, so the outermost shell of the sodium ion becomes the second electron shell, which has eight electrons in it.
The octet rule has been satisfied. On the left, a sodium atom has 11 electrons. In table salt, NaCl, this electron comes from the sodium atom.
Now the chlorine ion has the same number of electrons as the nearest noble gas, argon. The electron arrangement of the new species that results is as follows:. Certain salts are referred to in physiology as electrolytes including sodium, potassium, and calcium , ions necessary for nerve impulse conduction, muscle contractions and water balance. Many sports drinks and dietary supplements provide these ions to replace those lost from the body via sweating during exercise.
Improve this page Learn More. Skip to main content. Module 2: Chemistry of Life. Search for:. Ionic Bonds Learning Outcomes Describe the characteristics of ionic bonds and identify common ions.
Video Review This video shows how ionic compounds form from anions and cations. Try It. Did you have an idea for improving this content? An atom that has gained electrons and has a negative charge is an anion. An atom that has lost electrons and has a positive charge is a cation. When an atom has equal numbers of positive and negative particles, it has a neutral charge. But if an atom has extra electrons or is missing electrons, it is known as an ion, and it may bear a positive or negative charge.
In simple terms, if there are no electrons, the atom has a positive charge. The sodium atom wants to lose an electron and the chlorine atom wants to gain an electron. When the two atoms come together the electron from the sodium atom jumps into the gap in the outer shell of the chlorine atom. However, both ions now have eight electrons in their outer shell.
What charge does sodium ion have? Category: science chemistry. A neutral sodium atom, for example, contains 11 protons and 11 electrons. Atoms that gain extra electrons become negatively charged. What ion does sodium turn into and why? What is the charge of sodium in nacl? What are the two types of ions? How do you find an ion symbol? How many ions are in sodium? How do you know if an ion is positive or negative? What attracts sodium chloride? What is the function of sodium ion in human body?
Function of sodium ions. Which type of bond is present in NaCl? Is sodium chloride an ion?
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