Chemistry Chapter 5
Which group of elements was discovered by Strutt and Ramsay?
noble gases
almost entirely unreactive
noble gases
What can be removed from an atom if ionization energy is supplied?
an electron
An element that has the electron configuration [Ne]3s23p5 is in Group
17
An element that has the electron configuration [Ne]3s23p5 is in Period
3
What is the difference in atomic number between He and Ne?
8
The person whose work led to a periodic table based on increasing atomic number was
Moseley
Which noble gas has the greatest atomic number?
Rn
radioactive
actinides
In nature the alkali metals are found only in compounds because they
are very reactive elements
On most periodic tables, the lanthanides and actinides appear
below the main portion
Across a period in the periodic table, atomic radii generally
decrease
as you go down the periodic table, electron affinity ______ because _______
decreases; atomic radius increases, more difficult to add electrons
as you go down the periodic table, the electronegativity ______ because _______
decreases; dependent upon atomic radius
as you go down the periodic table, ionization energy _____ because _____
decreases; larger number of energy levels
as you go across the periodic table , the atomic radius _____ because _____
decreases; stronger nuclear force
energy charge that happens when an atom acquires an electron
electron affinity
measure of an atoms ability to attract an electron
electronegativity
One of the least electronegative elements would be found on the periodic table in
group 1 period 7
An element with the smallest anionic (negative-ionic) radius would be found on the periodic table in
group 17 period 2
charge of +2 when forming ionic compounds
group 2; alkaline earth metals
In which group is an element that has an outer-level electron configuration consisting of one electron in the d orbital and two electrons in the ns orbital?
group 3
diatomic
group seventeen; halogens
The atomic radius of an atom that is chemically bonded to an identical atom is equal to
half the distance between the nuclei
Nonmetallic elements in Group 17 that react with most metals to form salts are
halogens
Very strong oxidizers
halogens
As the atomic numbers of the metals of Group 1 increase, the ionic radii
increase
Down a group in the periodic table, atomic radii generally
increase
Across a period in the periodic table, ionization energy generally
increases
as you go across the periodic table, electron affinity ____ because _____
increases; increasing nuclear charge
as you go across the periodic table, ionization energy ____ because ______
increases; increasing nuclear charge
as you go down the periodic table, the atomic radius ___ because _________
increases; larger number of energy levels
as you go across periodic table, the electronegativity ______ because _______
increases; smaller atomic radius has stronger nuclear force
Down a group in the periodic table, the change in ionization energy is due to
increasing electron shielding
energy required to remove an electron from a neutral atom or ion
ionization energy
rare, high densities, used for industrial purposes
lanthanides
Elements in the s and p blocks of the periodic table are called
main group elements
To which group does hydrogen belong?
no group
The periodic law states that the physical and chemical properties of elements are periodic functions of their atomic
numbers
A repeating pattern is referred to as
periodic
In developing his periodic table, Mendeleev listed on cards each element's name, atomic mass, and
properties
Mendeleev's periodic table did not list all elements in order of increasing atomic mass because he grouped together elements with similar
properties
An element found in groups 312 of the periodic table is classified as a(n)
transition metal
The outer-level electron configuration of a neutral alkaline-earth metal atom consists of
two electrons in the s orbital
Mendeleev predicted that the gaps in his periodic table represented
undiscovered elements
An electron that is in the highest energy level of an atom and determines the atom's chemical properties is called a(n)
valence electron
Elements in Group 18 have
very low reactivity
