An electron acceptor is a cathode (negative charge). An anode (positive charge) is sometimes called an electron donor. The cathode is the electrode in the battery with the negative (-) terminal. The link you have been given is veery good. The anode is the electrode with the positive (+) terminal showing in the battery. If it then lights the LED is hooked up correctly and is good. If the LED lights up it is hooked up correctly. The Cathode is the positive or oxidizing electrode that acquires electrons from the external circuit and is reduced during the electrochemical reaction. Increase the voltage until 10 ma or so flows. The Anode is the negative or reducing electrode that releases electrons to the external circuit and oxidizes during and electrochemical reaction. A good way to test your LED's is to put one in series with a resistor. These definitions are true whether you have a electrolytic or galvanic cell. Anode: The electrode where oxidation occurs. The LED will be hooked up correctly if current is forced through the diode in what is usually the backwards direction for diodes. Cathode: The electrode where reduction occurs. You are in danger of shorting something if you hook up the LED backwards. ![]() How do you know that the flag points to the cathode with the kit LED's?This seems unusual to me. Perhaps the leds are used and were cut out of a circuit. There are many facturing reasons why the flag is the cathode, There is no necessary reason why the short lead is the cathode. In the usual LED the flag AND the short led are connected to the cathode. Did I get the wrong rated LEDs? Am I in danger of shorting something? A picture has been posted at: " In the others I bought, they point to the anode. In the kit's LEDs, the flag points to the cathode. (the “Gold Book”) Blackwell Scientific Publications: Oxford, 1997."I noticed that inside the head of the LED, there is a triangular "flag" that points in one direction. International Union of Pure and Applied Chemistry, IUPAC Compendium of Chemical Terminology, 2nd ed. Maybe the person who made the statement compared a 20 years old common cathode to a brand new common anode. Notes and Records of the Royal Society of London 1961, 16, 187–220. From the LEDs point of view, they dont even 'know' how theyre connected. The density and thickness of electrode is considered as an important factor in commercial batteries to get higher energy density. The cathode is also called the positive terminal. In addition, there are many systematic researches on the properties of electrode itself (cathode, and anode, ) to design a high performance full cell. Thus, the cathode is the electrode where reduction occurs. The word cathode comes from the Greek κάθοδος ( kathodos), meaning ‘descent’ or ‘the way downward’, which today refers to the movement of electrons down from the circuit into the electrode where they facilitate electrochemical reduction of the positive ions in the electrolyte solution at the surface of the cathode. Anode is where more anions are, and cathode is where more cations are found (in reference to the component). Thus, our positive voltage comes from the more negative end of the diode. The anode is also called the negative terminal. The cathode is more negative than the anode, but it is more positive than ground. Thus, the anode is the electrode where oxidation occurs. Meanwhile, in a traditional cell, the positive ions resulting from the same oxidation enter into the electrolyte solution. The word anode comes from the Greek ἄνοδος ( anodos), meaning ‘ascent’ or ‘the way upward’, which today refers to the movement of electrons up into the circuit after being released from the electrode material by oxidation. In the course of my own study of electrochemistry, I thought other students may find this information helpful in keeping everything straight. The following is a brief summary of their etymology and their meaning as it stands today in electrochemical circuits. As scientists have learned about how electrochemistry works, the definitions have evolved somewhat. ![]() C (athode) and r (eductio) don't start with vowels. ![]() I remember them as a (node) and o (xidation) are both vowels. Similarly, anode is the electrode where oxidation is occuring. Its electrostatic sign can be positive or negative. A delightful (and highly recommended) historical account of how these words were conceived by Faraday and his associates can be found in Faraday Consults the Scholars: The Origins of the Terms of Electrochemistry by Sydney Ross. In electrochemisty, cathode is the always electrode where reduction is occuring. The terms “anode” and “cathode” were first published by Michael Faraday, F.R.S.
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