Sodium has the atomic number 11
how many electrons are in a sodium ion, which has the symbol na+?
a)10
b)11
c)12

Select the correct answer. which statement applies only to the axial skeleton, not the appendicular skeleton? a. it contains a pivot joint. b. it has muscles attached that work in pairs. c. it contains red bone marrow. d. it possesses fossa for bone articulation. e. it protects the heart and lungs.