Question

An element has electronic configuration 2, 8, 7. 

(a) To which group and period of the long form of Periodic Table does it belong? 

(b) What is atomic number of this element? 

(c) Is it metallic or non-metallic and why? 

(d) Identify the element. 

(e) Name an element chemically similar to this element.

Answer 1

(a) Element belongs to 17 group and 3 period. 

(b) Atomic number of this element is 17 because atomic number is equal to total electrons present in it. 

(c) It is non-metallic because it has 7 electrons in its valence shell so it can gain only one electron to complete its octet. 

(d) This element is Chlorine. 

(e) Bromine is chemically similar to this element because bromine and chlorine are the elements of same group.