Answer the question, with the help of the following: a) Hard solid b) Melting point above 450 K c) six allotropic forms are known d) Low electrical conductivity, e) Mass number12. Which is the element?

Some information related to the elements of the p block in the 17th group of the periodic table are given in the table below. Complete the able and analyse the following questions. a) What is the family name of element belonging to 17th group? b) what is their common valency? c) Which element has the highest electronegativity? d) Which element has highest ionisation energy? e) List out the name and chemical formula of the compounds formed by this elements with s block elements. '(##VPU_TTT_CHE_X_P01_C01_E02_002_Q01##)'

The band gap at 300K of crystals A, B, C, D is 5.5, 1.2, 0.67 and 0.1 units respectively. Answer the fol lowing questions based on this information.In the above case, which crystal will have the highest electrical conductivity at 300K? Why?

In which of the following properties did Be shows similarities with Al? a) Both are comparatively stable in air. b) They have no tendency to form peroxide and superoxides. c) Both provide colour to Bunsen flame. d) Both form coloured solution in NH_(3) e) The oxides and hydroxides of both elements are amphoteric.