Unit 3 - Periodic Table Flashcards
Atomic Radius
the distance between the center of an atom’s nucleus and the outside edges of its outermost energy level.
Ionic Radius
the distance between the center of an ion’s nucleus and the outside edges of its outermost energy level.
Ionization Energy
the amount of energy needed to remove the outermost electron of an atom.
Electron Affinity
the amount of energy released when an electron is added to an atom.
Electronegativity
a measure of how attractive an atom is to a free electron.
What is the term for rows of a Periodic Table?
Period
What is the term for columns of a Periodic Table?
Group or family
What is the trend for atomic radius?
Increases to the left and down
What is the trend for ionic radius?
Increases to the left and down; remember that trend is interrupted when sign of ion changes but then reestablishes itself.
What group is not included in the ionic radius trend?
Noble gases because they do not form ions
What is the trend for ionization energy?
Increases to the right and up
What is the trend for electron affinity?
Increases to the right and up
What is the trend for electronegativity?
Increases to the right and up
What group does not participate in the electronegativity trend?
Noble gases. They are considered to have an electronegativity value of 0.
Soft; Highly reactive, especially with water
Alkali metals
Soft; Fairly reactive with water
Alkaline earth metals
Shiny; Highly conductive of heat and electricity; Most hard and solid
Metals
Properties are a combination of metallic and nonmetallic properties
Metalloids
Mostly gases; poor conductors of heat and electricity
Nonmetals
All but two are gases; highly reactive; when found in nature, bound in pairs
Halogens
All are gases; do not react except under very special circumstances
Noble gases
Lose electrons when forming ions
Metals
Gain electrons when forming ions
Nonmetals
Forms positive ions
Metals
Forms negative ions
Nonmetals
Sign of charge when gaining electrons
Negative
Sign of charge when losing electrons
Positive
What happens to the size of an atom when it loses electrons?
The ion is smaller because of the decrease in total repulsive force between the electrons, which are then able to draw in closer to the nucleus, reducing the overall size.
What happens to the size of an atom when it gains electrons?
It becomes a bigger ion. Adding an electron increases the overall repulsion between the electrons, which forces them to move farther apart and thus farther from the nucleus, increasing the overall size.
Group 1 has _____ valence electron
1
Group 2 has ______ valence electrons
2
Group 13 has _______ valence electrons
3
Group 14 has ________ valence electrons
4
Group 15 has ______ valence electrons
5
Group 16 has _______ valence electrons
6
Group 17 has _________ valence electrons
7
Group 18 has _________ valence electrons.
8
The metals are to the ___________ of the stair-step line.
left
The nonmetals are to the _________ of the stair-step line.
right
What elements are touching (have a side on) the stair-step line?
Metalloids
What is the one element that is touching the stair-step line that is a metal rather than a metalloid?
Aluminum (Al)
What is the one nonmetal to the left of the stair-step line?
Hydrogen (H)
What is the name of Group 1?
Alkali metals
What is the name of Group 2?
Alkaline earth metals
What is the name of Group 14?
Carbon family
What is the name of Group 15?
Nitrogen family
What is the name of 16?
Oxygen family/Chalcogens
What is the name of group 17?
Halogens
What is the name of group 18?
Noble gases
What is the name of groups 3-12?
Transition metals
What is the name of Groups 1, 2, 13-18?
Main group elements
What is the name of the two rows underneath the main periodic table?
Inner transition elements
What is the name of the top period of the inner transition metals?
Lanthanides
What is the name of the bottom period of the inner transition metals?
Actinides
What element’s existence did Mendeleev predict, and why was he able to do this?
Germanium, because he observed the periodicity of elements when arranged in order of increasing atomic mass. This allowed him to deduce the existence of missing elements.
What is the modern periodic table organized by?
atomic number (number of protons)
First person to organize elements; made triads of three similar elements
Johann Dobereiner
Organized elements by atomic mass; showed that properties repeat every 7 elements, which called the Law of Octaves
John Newlands
Organized elements by atomic mass and predicted existence and properties of unknown elements based on gaps in the table; known as the Father of the Periodic Table
Dmitri Mendeleev
Reorganized elements by atomic number rather than atomic mass
Henry Moseley
Trend for reactivity among metals
Increase as you down left and down
Trend for reactivity among nonmetals
Increase as you go up and to the right (does not count nonmetals)
Explain the atomic radius trend.
Atomic radius increases as you go down a group because each new period represents a new energy level being added on. It decreases as you go to the right because of increasing attraction between growing numbers of protons and electrons over the same distance.
Explain the ionic radius trend.
Ionic radius increases as you go down a group because each new period represents a new energy level being added on. It decreases as you go to the right because of increasing attraction between growing numbers of protons and electrons over the same distance. However, as you go to the right, at the point where you reach the first negative ion, it is bigger than the previous one because it is negative. The pattern reestablishes itself after that as each one is smaller than the previous one.
Largest atomic radius
Francium
Smallest atomic radius
Helium
Largest metal ion
Francium
Smallest metal ion
Beryllium
Largest nonmetal ion
Iodine
Smallest nonmetal ion
Fluorine
Explain the trend for ionization energy
As you go down a group, the farthest electrons are farther away from the nucleus, making them easier to remove, and giving the atom a lower ionization energy. As you go right, there is an increasing number of protons and electrons over the same distance, so attraction increases, and ionization energy increases.
Does higher or lower ionization energy represent easier to remove?
Lower
Largest ionization energy
Helium
Smallest ionization energy
Francium
Explain the trend for electron affinity.
It decreases as you go down a group because the electrons are being added to a farther energy level where they are less attracted to the nucleus. It increases as you go right because the atoms are getting closer and closer to a full outer shell.
Which group has an electron affinity of zero?
Noble gases
Greatest electron affinity
Fluorine
Lowest electron affinity
Francium
Explain the trend for electronegativity.
It increases as you go right because the atoms are getting closer and closer to a full shell. It decreases as you go down, because the electron would be added to a farther energy level.
Element with highest electronegativity
Fluorine
Element with lowest electronegativity
Francium
Which group does not have an electronegativity value?
Noble gases
