Why is xenon monatomic but bromine is diatomic

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

Choose all the answers that apply. ionic compounds dissolve easily in water do not dissolve in water have low melting points have high melting points conduct electricity when melted

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?