Chapter 8: Periodic Properties Of Elements Flashcards
For transition metals what electrons do we consider as valance electrons?
Electrons in the outermost principal energy level as well as the outermost d electrons
What do chemical properties depend on?
On its valance electrons
Why do elements in a column of the periodic table have similar chemical properties?
They have the same number of valance electrons
Define core electrons
Electrons in complete principal energy levels, and complete d and f sublevels, not including valance electrons
What elements does the f block consist of?
Lanthanides and actinoids
What does the number of columns in a block correspond to?
The maximum number of electrons that can occupy the particular sulevel of that block
Define valance electrons
The electrons important in chemical bonding. For the main group elements, these electrons are in the outermost principal energy level
What is the row number in the periodic table equal to?
The number (or n value) of the highest principal level
The inner electron configuration is the _____ _____that precedes it
Noble gas
What is the outer electron configuration?
The configuration of the electrons beyond the previous noble gas
The principle quantum number of the d orbital being filled across each row in the transition series if equal to…?
The row number minus one
For the first transition block series the d blocks outer configurations is 4s2 3dx with two exceptions which are? Why do these exceptions occur?
Cr (4s1 3d5) and Cu (4s1 3d10)
The reason this occurs is because 3D and 4s are very closely spaced energy levels and the stability associated with half filled or completely filled sublevel.
When a quantum level is completely full, the over all energy of the electrons that occupy that level is particularly _____. Therefore, those electrons ______ lower their energy by reacting with atoms or molecules, so the corresponding atom is relatively _____ or _____
Low
Cannot
Inert
unreactive
Elements with electron configurations close to that of noble gasses are the most reactive because…?
They can attain noble gas electrons configurations by losing or gaining a small number of electrons.
(Ions/atoms strive to be stable like noble gasses?)
Forming cations always requires ____.
Energy
Forming a ion with noble gas configuration _____favourable in terms of the initial energy needed because forming cations always _____ energy, but the payoff is greater than the cost energy wise.
Isn’t
Requires
How do you measure the nonbonding or van der waals radius?
By measuring the distance between to adjacent atoms that are touching which can be determined from the solids density. This distance is twice the radius of the atom
(Note this must be done with only a single element present
Which 2 names of ways can you measure atomic radii?
- Non bonding atomic radius or van der waals radius
2. Bonding atomic radius or covalent radius
How is the bonding atomic radius or the covalent radius defined for non metals?
One half of the distance between two of the atoms bonded together
How is the bonding atomic radius or the covalent radius defined for metals?
One half of the distance between two of the atoms next to each other in a crystal of metal
What does atomic radius refer to?
A set of average bonding radii determined from measurements of a large number of elements and compounds
The bonding atomic radius represents….? And is always ____ than the van see waals radius
The radius of an atom when it is bonded to another atom
Smaller
As we move down a column (or family) in the periodic table, atomic radius ______
Increases
As we move to the right across a period (or row) in the periodic table, atomic radius_____
Decreases
Define effective nuclear charge (Z)?
The average or net charge experienced by an electron
What is the equation for effective nuclear charge?
Zeff = z - S
What are the two types of shielding?
1) the shielding of the outermost electrons by the core electrons
2) the shielding of the outermost electrons by each other
Core electrons efficiently _____ electrons in the outermost principal level from the nuclear charge, but outermost electrons _____ efficiently ____ one another from nuclear charge
Shield
Don’t
Shield
As we move down an column in the periodic table, the principal quantum number (n) of the electrons in the outermost principal energy level ____, resulting in a _____ orbitals and therefore a _____ atomic radii
Increases
Larger
Larger
As we move right across a row in the periodic table, the effective nuclear charge (Zeff) experienced by the electrons in the outermost principal energy level ____, resulting in a _____ attraction between the outermost electrons and the nucleus and a _____ atomic radii
Increases
Stronger
Smaller
The radii of the transition metals ______ across each row. Why does this occur?
Stays rightly constant
It occurs because the number of electrons in the outermost principal level is nearly constant
What is lanthanoid contraction?
The trend towArd levelling off in size of the atoms in the third and fourth transition rows due to the ineffective shielding of the f sub level electrons
Cations are much _____ than their corresponding atoms
Smaller
Anions are much _____ than their corresponding atoms
Larger
What is an isoelectronic series of ions?
Ions with the same number of electrons
Define ionization energy (IE)
The energy required to remove an electrons from an atom or ion in it gaseous state
Ionization energy is always ____ because removing an electron takes _____.
Positive
Energy
The energy required to remove the first electron is called…?
The first ionization energy
The energy require to remove the second electron is called…?
The second ionization energy
Ionization energy generally _____ as we move down a column (or family) in the periodic table because electrons in the outermost principal level ______ ______ _____ from the positively charge nucleus and therefore held _____ tightly.
Decreases
Increasingly farther away
Less
Ionization energy generally _____ as we move right across a period (or row) in the periodic table because electrons in the outermost principal level generally experience a _____ effective nuclear charge (Zeff).
Increases
Greater
Boron has a ____ ionization energy than beryllium even though it lies to the right or beryllium in the same row. This exception is caused by…? Name a similar exception
Smaller
The change in going from the s block to the p block
Aluminum is smaller in ionization energy than gallium
Why is the third transition metal row generally higher in ionization energy than the first two transition metal rows?
In the transition elements, the charge of the nucleus increases substantially from one row for the next, but there is only a small increase in atomic size between row first and second rows, and no increase in size between the second and third rows. The outer electrons are therefore held more tightly in the third transition row then in the first two rows
The ionization energy will be very _____ if an electron is being removed from an ion or atom with a noble gas configuration
High
Define electron affinity (EA)
The energy required to remove an electron from a negative ion in the gas phase
Electron affinity (EA) of an atom is the energy ____ when an electron is added to the neutral atom in the gas phase
Released
The electron affinity is usually a _____ quantity because the coulombic attraction between the nucleus of an atom and the incoming electron usually results in the release of energy as the electron is gained
Positive
In some cases, the anion that forms in the gas phase is not stable, and EA is simply defined as being….?
Negative or less than zero (
Most groups of the periodic table do not exhibit any definite trend in _____ _____. Among the group 1 metals, however, electron affinity _____ as we move down a column (or family)
Electron affinity
Decreases
Electron affinity generally _____ as we move right across a row or period in the periodic table. One common exception to this is…?
Increases
When electrons must share an orbital their electrons affinity is less than it would be if they followed the trend
although oxygen is to the right of nitrogen in the same row, it has a ____ ionization energy. This is exception is caused by…? Name a similar exception
lower
the repulsion between electrons when they must occupy the same orbital (nitrogen has 3 3p electrons so none share orbitals where as oxygen has 4 3p electrons so one orbital has two electrons)
silicon and selenium and the elements before them in their row
there is a small _____ in ionization energy going from the d block to p block. This is because…?
decrease
the p electrons are shielded form the nucleus better than the d electrons of the same row
As we move right across a row or period in the periodic table, ionization energy _____, and electron affinity becomes more _____; therefore, elements on the left side of the periodic table are ______ likely to lose electrons than elements on the right side of the table (which are _____ likely to gain them
Increases
Positive
More
More
As we move to the right across a row or period in the periodic table metallic character _____.
Decreases
As we move down a column or family in the periodic table, metallic character _____ (because ionization energy ______ which make electrons more likely to be _____ in chemical reactions)
Increases
Decreases
Lost
