Classity each of the following as element, compound, or mixture

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

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons

The fact that the total amount of energy in a system remains constant is a(n)