2,8g of iron is burnt in air, 4,0g of iron oxide is formed. What is the empirical formula. Plz it's urgent​

Which of the following compounds does not contain molecules? question 2 options: co2 h2 nacl h2o

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.

The organism shown is a free-living one that is anchored to the bottom of ponds and streams during one stage of its life cycle what is the common name for the group to which this organism belong