Which elements are most likely to be gases at room temperatrue?

How many miles of water are produced if 5.43 mol pbo2 are consumed

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.

What are fossils of organisms that existed over a wide area but only for a limited time period called?