Answers and Explanations

DIAGNOSTIC TEST

1. Part A

1 . A

Atomic  mass    is  the averaged    mass    of  the atoms   of  an  element,    taking  into    account the relative

abundance   of  the various isotopes    in  a   naturally   occurring   substance.

2 . D

Electronegativity   is  a   measure of  the ability of  an  atom    to  attract the electrons   in  a   bond.   A

common  scale   is  the Pauling scale.

3 . C

The atomic  radius  is  defined as  the average distance    between a   nucleus and the outermost

electrons.  It  is  usually measured    as  half    of  the distance    between two nuclei  of  an  element in  its

elemental   form.

4 . B

The atomic  number  is  defined as  the number  of  protons in  a   given   element.    It  defines an

element.

5 . E

The ionization  potential,  or  ionization  energy, is  the energy  required    to  remove  an  electron

from    the valence shell   of  a   gaseous atom.

6 . D

Krypton is  the first   element with    a   filled  4p  orbital,    so  the element must    fall    after   it  in  the

periodic    table.  Rb  is  the only    element with    enough  electrons   to  have    a   filled  4p  subshell.