What substance has a mass of 9.5g and volume of 2.1cm^3

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

What is the mass of 8 moles of sodium atoms

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.