What is the formula mass of beryllium chloride , becl2? express your answer to four significant figures and include the appropriate units?

3. if the dartboard below is used to model an atom, which subatomic particles would be located at z?

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.

Particles vibrate in a rigid structure and do not move relative to their neighbors.