I need help please
Why do you think you with the PH paper before you ignite the match?

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?