Vocabulary
Define Ionization Energy
The energy required to REMOVE 1 electron from a neutral atom.
Do successive ionization energies and electron affinities increase, decrease or stay the same?
Increase.
How do electron configurations within a group compare?
Generally the configurations of the outermost electron shells of elements within the same group are the same.
Name 3 groups that form cations and how many electrons each group loses.
Groups 1 (lose 1 electron),
Groups 2 (loses 2 electrons)
Groups 13 (loses 3 electrons)
How do the properties of alkaline-earth metals compare with alkali metals?
Alkali-earth metals are less reactive than alkali metals.
(50 bonus points for each of the following mentioned:
- stronger, harder, denser, higher melting points)
Define Cation and Anion and how they are created.
Cation - positively charged ion created by losing one or more electrons.
Anion - negatively charged ion created by gaining one more more electrons.
Define electron affinity AND describe how and why it changes as you move across a period and down a group.
Electron affinity is the change in energy when you add an electron to an atom. A negative change in energy means energy is released.
Electron affinity increases (becomes more negative) across a period and decreases (becomes less negative) down a group.
It increases across a period because the atom is closer to achieving a complete outer shell, and therefore more stable.
It decreases down a group because it is further from the nucleus so less energy is released.
An element with the general electron configuration ns^2 np^1 for its outermost electrons would be in which group?
13. The s block is full. The d block is full or not used. It would be in the first group in the p block, which is group 13.
Name 2 groups that form anions and how many electrons each group gains.
Groups 16 (gains 2 electrons)
Groups 17 (gains 1 electrons)
Why are nobel gasses relatively unreactive?
Because their outer shells are completely filled.
Define Valence Electron(s)
electrons in the outermost shell of an atom that are available to be lost, gained or shared in the formation of a chemical compound.
These electrons are found in the s and p orbitals of the highest energy level for the element.
Tell how the radius of an atom changes as you move across a period and down a group. Explain why.
The radius decreases across a period because there is a greater positive charge in the nucleus that has a greater pull on the electrons.
The radius increases down a group because there are more electron shells and the inner shell electrons shield the outer shell electrons from the nucleus's pull.
What is the outer shell configuration for the element in Group 13, Period 5?
4d^10 5s^2 5p1
Which Anion is least likely to form:
S1- (group 16, period 3)
O2- (group 16, period 2)
Group 16 elements like to form a 2- charge. Therefor S1- is least likely to form.
How many valence electrons are in a neutral atom of Arsenic (Period 4, Group 15)?
5
Define Atomic Radii
One half the distance between the nuclei of identical atoms that are bonded.
Tell how the ionization energy of an atom changes as you move across a period and down a group. Explain why.
The ionization energy increases across a period because of the increased charge of the nucleus holding the electrons in place.
The ionization energy decreases down a group because the inner shell electrons shield the valence electrons from the pull of the nucleus, making it easier to remove electrons.
Without looking at the periodic table, identify the period, block, and group in which the element is located:
[Xe]4f^14 5d^10 6s^2 6p^5
Period: 6
Group: 17
Group: p
Which cation is least likely to form:
Al+ (group 13, period 3)
Cl+ (group 17, period 3)
Cl+.
Electronegativity (ability to lose electrons) increases across a period, meaning it is less likely to happen.
Additionally, we know that Cl normally forms the Cl- ion because it likes to gain 1 electron.
How do values of successive ionization energies compare and why?
Each successive ionization energy is larger than the previous one because each successive electron must be removed from a particle with a greater positive charge.
Define Electronegativity and state how it is communicated
Electronegativity is the measure of the ability of an atom in a chemical compound to attract (gain) electrons (becomes negatively charged) from another atom in the compound.
Atoms are assigned a number in relation to Fluorine (which is assigned the number 4 and is the most electronegative.)
Tell how the electronegativity of an atom changes as you move across a period and down a group. Explain why.
Electronegativity increased across a group because the nucleus's increased positive charge (and therefore pull) makes it easier to attract electrons.
Electronegativity decreases down a group because the increased inner shell electrons decrease the effect of the nucleus's positive charge, making it harder to pull in extra electrons.
Without looking at the periodic table, write the expected outer electron configuration for the element in group 12, 6th period.
4f^14 5d^10 6s^2
K+ (period 4, group 1) and
Ca2+ (period 4, group 2
each have 18 electrons surrounding the nucleus.
Which would you expect to have a smaller radius and why?
Ca2+ because it has a greater positive charge from the nucleus pulling on the electrons, which will pull them closer to the nucleus.
Which would have the smallest anionic radius? Why?
Period 2, Group 17
Period 2, Group 13
Period 4, Group 1
Period 2, Group 17
The greatest positive charge of the nucleus combined with the least electron shielding means that the radius would be the smallest.