An element to 3rd period and 17th group of the periodic table, find out a. The electronic configuration of element on its left and right b. Its valence electrons c. Its size with in composition with neighboring elements
Since the element is in group 17 So, it is a halogen. Halogens start from the second period. Counting the periods and matching it with the periods of that of halogens, we find that period 3 has Chlorine. So, the element is Chlorine. Element X has 17 electrons i.e. 7 electrons in its valence shell, so it will accept 1 electron, hence, its valency is 1. The electronic configuration of chlorine is 1s22s22p63s23p6. Element X is chlorine which requires only one electron to complete its octet. Hence, its valency is 1. The first two electrons will go in the 1s orbital. Since 1s orbital can only hold two electrons, the next two electrons for Chlorine will move into the 2s orbital. The next six electrons will move in the 2p orbital. The p orbital can hold up to six electrons. The further two electrons will occupy the 3s. Since the 3s is full, the remaining 5 electrons will move into a 3p orbital.
