Which of the following statements is true? a. the nitrogen cycle is the most important cycle for life. b. the oxygen cycle is the least important cycle for life. c. life can be sustained without any of the cycles for life present. d. all cycles of matter are equally important for life to be sustained.

This chart represents the melting point of several substance. what besy explains the high melting point of the salt?

Which of the following electromagnetic waves can create ions?

Me i dont know what to do! the table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.