In chemistry class what do we mean when we refer to a mole

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?

Which element would mostly likely have an electron affinity measuring closest to zero

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of tthe table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 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.