Electronegativity
This trend increases as you move left → right across a period and bottom → top on the periodic table.
electronegativity
Atomic radius increases in this direction on the periodic table.
down a group and to the left across a period
The term for electrons on the inner shells that block the nucleus from pulling strongly on valence electrons.
shielding effect
An anion is an ion with this charge.
negative charge
The symbol Δχ (Delta Chi) represents this in electronegativity calculations.
electronegativity difference
Of the following, this element has the highest electronegativity: Aluminum, Rubidium, Oxygen, Lithium.
Oxygen
Of Selenium, Aluminum, Cesium, and Rubidium, this element has the largest atomic radius.
Cesium
Groups on the periodic table run in this orientation, and periods run in this orientation.
groups = vertical columns, periods = horizontal rows
A cation is ______ than its parent atom, while an anion is ______.
a cation is smaller; an anion is larger
State the formula used to calculate electronegativity difference.
Δχ = |χ₁ – χ₂|
This is the element with the highest overall electronegativity on the periodic table.
Fluorine
Explain why atomic radius increases going down a group.
atoms gain energy levels, so valence electrons are farther from the nucleus
Explain how the shielding effect changes as you go down a group.
it increases because more inner electrons block the nucleus
Explain why cations shrink in atomic size.
they lose electrons, reducing electron repulsion and pulling remaining electrons closer to the nucleus
Using the equation, estimate the electronegativity of Magnesium Chloride, and determine whether or not it will share or steal electrons.
3-1.2= 1.8, steal electrons (thief)
Describe why electronegativity increases going up a group.
there are fewer energy levels, so valence electrons are closer to the nucleus and less shielded
Describe the relationship between shielding effect and atomic radius.
more shielding reduces attraction from the nucleus, increasing atomic radius
What happens to electronegativity as shielding increases—and why?
electronegativity decreases because the nucleus cannot attract bonding electrons as strongly
Explain why anions grow in atomic size.
added electrons increase repulsion and spread the electron cloud outward
Using the electronegativity equation, determine the bond type between Nitrogen (χ = 3.0) and Hydrogen (χ = 2.1) by calculating the electronegativity difference (Δχ).
(Δχ)= 3.0-2.1=0.9
Polar covalent bond
Explain how electronegativity and atomic radius interact with each other.
as atomic radius decreases, electronegativity increases because the nucleus more strongly attracts bonding electrons
Draw/describe where the nucleus, core electrons, valence electrons, and ‘shield’ are located in an atom.
the nucleus is in the center, core electrons occupy inner shells, valence electrons occupy the outer shell, and shielding comes from inner electrons blocking nuclear pull
Fully explain how charges (+/–) on ions affect atomic radius.
cations (positive ions) lose electrons and become smaller; anions (negative ions) gain electrons and increase electron–electron repulsion, becoming larger than the parent atom
Predict which is larger: Cl or Cl⁻. Explain.
Cl⁻ because gaining an electron increases repulsion and radius
1. What element has the highest electronegativity on the periodic table?
2. Calculate the electronegativity difference (Δχ ) between this element and Hydrogen.
3. This bond between fluorine and hydrogen would indicate that it has a strong _______ bond.
1. Fluorine
2. (4.0-2.1)= 1.9
3. ionic