An element's atomic number is the
a. mass of the atom.
b. number of protons in an atom's nucleus.
c. weight of the atom.
d. sum of the protons and neutrons in an atom.

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.

Which of the following best supports the concept that genetic information is passed on to offspring from both of their parents, not just one?

Word equation for k+ h2o yield koh + h2