[Music] hi and welcome back to free science lessons by the end of this video you should be able to describe how electrons are transferred during ionic bonding between group two metals and group six non-metals you should then be able to draw Dot and cross diagrams to show ionic bonding in the last video we saw that ionic bonding takes place when a metal reacts with a non-metal we looked at ionic bonding between a group one metal such as lithium and a group seven non-metal such as Florine we saw that the electron in the outer energy level of the lithium atom moves to the fline atom at the end of this reaction we've produced the one positive lithium ion and the one negative fluide ion both the lithium ion and the fluide ion now have a full outer energy level in other words they have the stable electronic structure of a noble gas so in this video we're looking at ionic bonding between a group grou two metal and a group six non-metal a good example is the reaction between the group two metal magnesium and the group six non-metal oxygen I'm showing you a magnesium atom and an oxygen atom here the Magnesium atom has 12 positive protons and 12 negative electrons these charges cancel so the Magnesium atom has no overall charge the oxygen atom has eight positive protons and eight negative electrons again these charges cancel so the oxygen atom has no overall charge like all group two metals the Magnesium atom has two electrons in its outer energy level the oxygen atom has six electrons in its outer energy level just like all the elements in group six now when magnesium reacts with oxygen the Magnesium atom loses the two electrons and its outer energy level and these two electrons are transferred to the oxygen atom at the again the Magnesium atom still has 12 positive protons but now it only has 10 negative electrons this means that magnesium now has an overall two positive charge and we call this the magnesium ion looking at the oxygen atom we can see that oxygen still has eight positive protons but now oxygen has 10 negative electrons this means that oxygen now has an overall two negative charge and we now call this the oxide ion as you can see both the magnesium ion and the oxide ion have a full outer energy level in other words they've achieved this stable electronic structure of a group zero noble gas now we can also show this reaction using a DOT and cross diagram like this remember that in a DOT and cross diagram we only show the outer energy levels that's because only the outer energy levels are involved in the reaction so again here are the two electrons moving from the Magnesium atom to the oxygen atom and again we've made the magnesium ion and the oxide ion so to recap during ionic bonding group two metals lose two electrons forming a two positive ion and group six non-metals gain two electrons forming a two negative ion and again both ions now have a full outer energy level in other words the stable electronic structure of a group zero noble gas now in the exam you could be asked to show ionic bonding between any metal in group 1 or two and any non-metal in group 6 or 7 I'm showing you here the reaction between Lithium in group one and oxygen in group six lithium atoms have one electron in their outer energy level whereas oxygen atoms have six electrons in their outer energy level so in this reaction two lithium atoms each lose their outer electron and these two electrons are then transfer to one oxygen atom in this way both the two lithium atoms and the one oxygen atom achieve a full outer energy level here's the reaction between calcium in group two and Florine in group s calcium atoms have two electrons in their outer energy level whereas fline atoms have seven electrons in their outer energy level in this reaction the calcium atom loses its two outter electrons the two Florine atoms then gain one electron each and again both the calcium atom and the two fline atoms achieve a full outer energy level you'll find plenty of questions on this topic in my vision workbook which you can get by clicking on the link [Music] above