A zinc-carbon dry cell battery left and alkaline battery right. In rechargeable batteries, such as many lithium-ion batteries, this chemical process is reversible and the internal structure different which allows the batteries to be recharged.
Due to the ionic properties of salt water, scientists are now striving to exploit the ionic electricity-generating potential of salinity gradients where salt water and fresh water mix as a green source of energy generation for the future. What is a cation?
Meet The Author. Karen Steward PhD. Chosen for you. Electrode attracted to. Cathode negative. Anode positive. Formed by. One example is in the process of electrolysis , which involves an electric current passing through a material and producing a chemical reaction.
During electrolysis, the positively charged cations are attracted to a negatively-charged electrode called a cathode. Anions are attracted to a positively-charged electrode called an anode. The first records of the words cation and anion in English come from around the s. Remember: the number of electrons in a cation has gone down, resulting in a positive charge. The number of electrons in an anion has gone up, resulting in a negative charge. Many elements can take the form of either anions or cations depending on the situation.
Oxygen often exists in a neutral state, but oxygen atoms tend to form anions by gaining two electrons. Atoms of other elements also tend to form anions , including nitrogen , chlorine , and fluorine , among others. By contrast, atoms of calcium , magnesium , aluminum , and sodium tend to lose electrons and form cations. Remember, cations are positive ions—they are positively charged because they have lost one or more electrons and therefore have more protons than electrons. Anions are negative ions—they are negatively charged because they have gained one or more electrons and therefore have more electrons than protons.
Whether you need one-on-one or group study sessions, Dictionary Academy tutoring is custom-fit to meet your learning needs. Feedback Tired of Typos? Word of the Day. Meanings Meanings. Next "Fiddle" vs. Once again, the octet rule has been satisfied. In many cases, elements that belong to the same group vertical column on the periodic table form ions with the same charge because they have the same number of valence electrons.
Thus, the periodic table becomes a tool for remembering the charges on many ions. Note the convention of first writing the number and then the sign on a ion with multiple charges. This page was constructed from content via the following contributor s and edited topically or extensively by the LibreTexts development team to meet platform style, presentation, and quality:.
Learning Objectives Define the two types of ions. Cations A neutral sodium atom is likely to achieve an octet in its outermost shell by losing its one valence electron. On the left, a sodium atom has 11 electrons. Anions Some atoms have nearly eight electrons in their valence shell and can gain additional valence electrons until they have an octet.
0コメント