Which one of the following statements about solid cu (face-centered cubic unit cell) is incorrect?
a) it will conduct electricity.
b) there are two atoms per unit cell.
c) the number of atoms surrounding each cu atom is 12.
d) the solid has a cubic closest-packed structure.
e) the length of a face diagonal is four times the cu radius

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.