Coulombic Attraction / Zeff
What is the non-dominant factor affecting coulombic attraction?
size of charge (q1 and q2 in F = (q1 x q2) / (d x d))
Sort the following elements by periodic trend from lowest to highest, using their chemical symbols:
Atomic Radius - silicon (Si), chlorine (Cl), krypton (Kr), antimony (Sb)
Cl, Kr, Si, Sb
The elements in Group 5A of the Periodic Table:
A. form ions with charges of 5-
B. have 5 valence electrons
C. are known as the alkaline earth family
D. are all metals
B. have 5 valence electrons
Group number tells you number of valence electrons!
____________ is the concept that when elements are organized by atomic number, properties recur periodically.
What is periodicity?
Elements in Group 1A will likely form what ions? Draw the electron dot structure for a neutral atom and for an ion.
Elements in Group 1A will likely lose 1 electrons to form a +1 cation.
Before: Element symbol with 1 dot around it
After: Element symbol in brackets and a positive sign superscript with either 8 or 0 dots around it
What is the dominant factor affecting coulombic attraction?
distance (d in F = (q1 x q2) / (d x d))
Sort the following elements by periodic trend from lowest to highest, using their chemical symbols:
Ionization Energy - sodium (Na), sulfur (S), fluorine (F), radium (Ra)
Ra, Na, S, F
Based on the properties listed below, select which element(s) are metals.
A. Element 1 is a dull solid that shatters when struck with a hammer.
B. Element 2 is a liquid that easily conducts electricity.
C. Element 3 is a shiny wire that ignites when exposed to water.
D. Element 4 is a gas that readily reacts with alkali metals.
B. Element 2 is a liquid that easily conducts electricity.
C. Element 3 is a shiny wire that ignites when exposed to water.
Look for properties of metal.
The _________ Rule states that elements with a full valence shell are relatively unreactive.
What is Octet?
What does inert mean?
chemically inactive
An example of Coulombic Attraction in an atoms is between which two subatomic particles?
Protons and electrons
Sort the following elements by periodic trend from lowest to highest, using their chemical symbols:
Electron Affinity - fluorine (F), aluminum (Al), xenon (Xe), gold (Au)
Which grouping of elements are all diatomic under normal conditions?
A. Carbon (C), Nitrogen (N), Oxygen (O)
B. Hydrogen (H), Lithium (Li), Potassium (K)
C. Fluorine (F), Bromine (Br), Iodine (I)
D. all of them
C. Fluorine (F), Bromine (Br), Iodine (I)
Remember Good Ol' Professor BrINClHOF
The most reactive elements on the table are the ____________ & ____________.
What are the halogens and alkali metals?
What periodic property is most opposite from Ionization Energy, based on definition?
Electron Affinity.
Ionization Energy deals with the lose of an electron to form cations. Electron Affinity deals with the gain of an electron to form anions.
How does effective nuclear charge charge moving left to right across a period?
It increases!
More protons but the same number of shielding electrons.
Sort the following elements by periodic trend from lowest to highest, using their chemical symbols:
Electronegativity - helium (He), nitrogen (N), calcium (Ca), rubidium (Rb)
He, Rb, Ca, N
All atoms experience Coulombic forces between their nucleus and electrons. Which of the following changes to an atom would result in the greatest increase in Coulombic force?
A. doubling the amount of protons in the nucleus
B. tripling the amount of protons in the nucleus
C. halving the radius of the atom
D. multiple answers are correct
C. halving the radius of the atom
F = (q1 x q2)/(d x d) = F
Halving the distance --> F = (q1 x q2)/(1/2d x 1/2d) = (q1 x q2)/(1/4 dxd) = 4F
Doubling protons --> F = (2q1 x q2)/(d x d) = 2F
Tripling protons --> F = (3q1 x q2)/(d x d) = 3F
____________ are known for being soft, brittle, and non-conductive.
What are the Chalcogens?
What makes an atom stable? What group do all elements want to be like?
They have a full valence shell / a full octet. Elements want to be like the noble gases.
Show all of your work!
What is the effective nuclear charge (Zeff) for Calcium (Ca) valence shell? Provide a statement explaining what your answer means.
# of protons - # of shielding electrons
20 - 18 = +2
The valence electrons feel the pull of 2 protons even though there are 20 in the nucleus.
Using effective nuclear charge, explain why the atomic radius trend changes the way it does going left to right.
One way to explain it is:
As you go left to right on the periodic table, the number of protons increases but the number of shielding electrons stays the same.
This causes the effective nuclear charge to increase going left to right.
An increased effective nuclear charge causes an increased coulombic attraction and thus a smaller atom.
Which of the following describes a chemical change?
A. Salt is added to water and dissolves.
B. Magnesium (Mg) loses its valence electrons.
C. Neon (Ne) is exposed to high voltage and emits orange light.
D. Water is put on a hot plate, creating a gas.
B. Magnesium (Mg) loses its valence electrons.
Creation of an ion (new substance) = chemical change
____________ is the charge from the nucleus that is negated by the repulsion of core electrons.
What is the Shielding Effect?
Explain what the ionization energy would look for for elements in Group 1A.
An element in group 1A would have a smaller first ionization energy than elements not in group 1A. An element in group 1A would have a large second ionization energy because after it looses 1 electrons it has a full shell underneath that becomes the valence shell.