Free point free point and have a nice day

Five students had to answer the question how are elements arranged in a periodic tabledamon: i think the elements are arranged by increasing massflo: i think the elements are arranged according to their properties sienna: i think the elements are arranged by when their discovers kyle: i think the elements are arranged according to how common they areglenda: i don't agree with any of themwho is right

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3