Place the following in order of increasing metallic character. rb cs k na

Video Transcript

So in the first part, we need to arrange the elements in order to get metallic character. Metallic character can be simply seen through their nature produce electrons and it is according to the atomic size. So we have option c c m, rubidium, sodium and potassium. So sodium is from period number 3. This is from 4 and then is rubidium 5 and cesium 6 and larger the period number larger that outside okay, you can simply understand so c c m have the highest atomic size, so it will lose electron more easily. After than rubidium than potassium and then sodium simple, you can simply write large to the atomic hides larger will be the metallic character. Higher will be metallic character in the second part we need. We need to classify the h. I means human iodide as and now is it a molecule element or molecular compound ionic compound? What so hi is actually ionic in nature, but it is a diatom molecule, diatomic molecule, so you can simply take the option that is molecular compound. Okay. So, actually in the question there is options not like 1 to 3. They are just simply written so izing molecule, whatever option molecule contain, will be the correct answer in the third 1. You need to define electron affinity, so electron infinity is about the gaining electron or any element which have the nature to gain that electrons. So we have options. Electron infinity is the lowest energy. All vital that occupy electrons. That is incorrect. Electron infinity is the energy associated with the formation of crystalline lattice of alternating thedie from the gaseous ion. That'S not correct. Electron infinity is the energy required to remove and electrons from an atom or iron. That'S also not correct, because it is removing. We need to gain electron so that the fourth option will be correct. That electron infinity is the energy associated with the gaining of an electron by an atom in the gaseous state. Okay, so option d 1 is correct because it's electron infinity is the energy amount of energy which any element required to gain the electron. Okay. So after that, we need to place elements in decreasing order of the metallic character. That is the depart and we have option phosphorus arsenic and potassium. So these 2 elements from the same group that is group number 15 and potassium is from group 1. So if you see their electronic configuration metallic character, as i said earlier in the first part, it's about losing electrons right now, we can simply divide them. There are many other character also, but for any element, this is the most general character. So if you see phosphors have less nature to lose electron, why? Because it has 35 electrons in the most out of mose cell. This is the electronic configuration that is 285 foot phosphorus for arsenic. It will be 28185 and potassium is 2881 point, so most easily loose electron will be potassium 1, so potassium will be highest motali character after that arsenic because of the larger size and then phosphorus. So this is the correct option. In the next part, we need to arrange elements according to their atomic radii, and these are the irons so simple, remember this 1 and ions will have larger size than their neutral atom and tation will have smaller size than their neutral ladder. What i'm saying like if we compare nitrogen with nitrogen negative, then nitrogen negative will have larger size. Why this negative and positive represent the number of electrons. If there is negative means, electron increase, a positive electron degrees, higher the number of electrons higher will be the atomic size because they will they will repel through the other electrons. Okay, so simply an ion. We have larger sides. So if we see the option, only n, 3 and n minus 1 point relate our reason. That is 3 negative means there will be. There will be 3 electron on this nitrogen and in n minus 1 only 1, so it will have a larger size higher. The number of electrons hydrobia size, so this is option correct in other options. Okay, no answer other is correct because in that case, as in s minus and s minus 2, they have more electro right. It should be larger size, but it's given like that. So it is incorrect and same with the other option. Okay, in the last part, we need to calculate the wave length wave length for what, for n 1 to n 3 transition, so we will use the formula that is 1 by wave length is equal to r h. That is a redberconstant 1 by 1 point. This 1 is 3 square and 1 n square okay. So if we put, the value here would be 33 square unsown square reder. Constant value is equal to 1.09710 raised to the power 7 point. Okay, it is in meter meter inverse. So if we calculate from this value, the value will be around 103 n m and you can see the options right in your question hear third. 1, so that will be the correct answer. We just need to put the value and solve this 1.