description of the atomic orbitals that are occupied in the lowest-energy state of the atom or ion
What is true for Group 2A elements?
they form doubly positive ion when they react, losing both their valence-shell s electrons
How do transition metals react with nonmetals?
react with nonmetals to form cations by first losing their valence shell s electrons and then losing one or more d electrons
Which is removed first? 4s or 3d?
What is the periodic trend for atomic radii?
increase down a column because successively larger valence-shell orbitals are occupied; adn decrease from left to right across row because effective nuclear charge increases across the row
Atoms __ when an electron is removed to form a cation.
because the electron is removed from a large valence-shell orbital and because there is an increase in the effective nuclear charge for hte remaining electrons
What is the cause for the expansion in size of anions in respect to their parent atoms?
due to decrease in effective nuclear charge adn increase in electron-electron repulsions that occur when extra electron is added
Where are hte lowest ionization energy values? highest?
and an increase from left to right
True or False: Ionization energy values can be positive and negative?
False; positive; energy must always be added to remove an electron from an atom
inner-shell electrons that shield the single valence electron from the nucleus
Relationship between Zeff and Ei?
small Zeff, small Ei
Why does hte graph show an irregularity in the graph, for instance, between boron and berrylium?
Nitrogen and oxygen?
A 2s electron is removed by from Be, but a 2p is removed from B. Because a 2s spends more time closer to the nucleus than a 2p, it is harder to remove; Thus, the Ei of Be is larger than that of boron
The same goes. Nitrogen's electron is removed from a half-filled orbital, whereas oxygen's electron is from a filled orbital
Why do the ionization energies get larger with each ionization step?
because it is much harder to pull a negatively charged electron away from a positively charged ion than from a neutral atom
Ionization energies are always __ because energy must always be __ to separate a negatively charged electron from the resultant positively charged cation.
Electron affinities are generally __ because energy is __ when a neutral atom adds an additional electron.
A positive energy change means __;
a negative energy change means __.
energy is added
energy is released
The more negative the Eea, the __.
greater the tendency of the atom to accept an electron and the more stable the anion results
What does it mean if the Eea is zero?
that element does not add an electron and the resulting anion is not stable
What is the period trend of Eea?
Group 7A elements have the most negative electron affinities, corresponding to the largest release of energy, while group 2A and 8A have near zero or positive electron affinities, corresponding to a small release or even an absorption of energy
increase in negativity from left to right, except for its at zero value for noble gases
Attraction between the additional electron and the nucleus favors a __, but the increase in electron-electron repulsions that results from addition of the extra electron favors a __.
What does less favorable mena in terms of Eea?
more positive Eea
What is sublimation?
conversion of solid to gas
In the born haber cycle, what is equal.
the sum of the energy changes of hte five steps and hte net energy change for the overall reaction
steps one, two and three have __ values and __ energy, while steps four and five have __ values and __ energy.
The largest contribution is step five, which measures__.
electrostatic forces between ions in the solid product--that is, the strength of the ionic bonding
The measure of hte electrostatic interaction energies between ions in a solid and thus the measure of hte strength of hte solid's ionic bonds is called __.
lattice energy U
By convention, what is lattice energy?
the amount of energy that must be added to break up an ionic solid into its individual gaseous ions, so it has a positive value
What is the relationship between lattice energy and the Born-Haber Cycle?
lattice energy is positive
step five in the cycle is negative U
The force F that results from the interaction of electric charges is described by __ and is equal to a constant __ times the __, divided by the __.
product of the charges on the ions, z1 and z2
square of the distance d between their centers (nuclei)
Within a series of compounds that have the same anion but different cations, lattice energy __ as the cation becomes smaller.
Within a series of compounds that have the same cation but different anions, lattice energy __ as teh anion size decreases.
What are the most powerful reducing agents?
Alkali metals are produced commercially by __ of their __, although the exact procedure differs for each element.
Both lithium metal and sodium metal are produced by __, which is __.
a process in which an electric current is passed through the molten salt
Alkali metals react rapidly with grouop 7A elements (halogens) to yield colorless, crystalline ionic salts called __.
True or False
The reactivity of an alkali metal increases as its ionization energy decreases.
All the alkali metals react rapidly with oxygen, but different metals give different kinds of products.
lithium + O2= oxide Li2O
sodium + O2= Na2O2
K, RB, and Cs form others.
This results in __, __, and __.
What is the reaction for an alkali metal with H2O?
2 M + 2 H2O--> 2 M++ 2 OH- + H2
What is the reaction with alkali metals and ammonia?
2 M + 2 NH3--> 2 M++ 2 NH2-+ H2
Which has higher melting points and densities? alkali or alkaline earth?
Halogens are (metal/nonmetal); (atomic/ diatomic); (gain/lose)?
__ are among the most reactive elements in the periodic table.
Unlike the metallic elements, what is the trend going down the family of halogens?
they are less rather than more reactive going down because of their generally decreasing electron affinity