Name: Date:
Student Exploration: Polarity and Intermolecular Forces
Vocabulary: dipole, dipole-dipole force, dipole-induced dipole force, electronegativity,
intermolecular force, ionic bond, London dispersion force, molecule, nonpolar, nonpolar
covalent bond, partial charges, polar, polar covalent bond, valence electron
Prior Knowledge Questions (Do these BEFORE
using the Gizmo.)
1. A big bully is having a tug-of-war with a small child.
There is a ball attached to the middle of the rope.
Toward whom will the ball move?
2. Two equally strong kids are having a tug-of-war. What do you expect to happen to the ball in
this situation?
Gizmo Warm-up
Just like in a tug-of-war, atoms that are bonded to one another pull
on the electrons they share. In the Polarity and Intermolecular
Forces Gizmo, you will explore how these opposing forces relate to
bond types and the forces between molecules.
To begin, drag the Na (sodium) and Cl (chlorine) atoms into the simulation area. Turn on Show
valence electrons. A valence electron is found in the outermost energy level of the atom.
1. Click Play ( ). What do you notice?
2. Which atom seems to be pulling more on the sodium’s one valence electron?
How do you know?
3. What happens to the colors of the simulated atoms, and what does this indicate?
, Get the Gizmo ready:
Activity A:
On the BOND POLARITY tab, click Reset ( ).
Bond polarity
Drag the atoms out of the simulation area.
Introduction: A neutral atom has the same number of protons as electrons. Atoms that gain
electrons become negatively charged, while those that lose electrons become positive. A polar
bond forms when shared electrons are pulled closer to one atom than another, causing the
bonded atoms to become partially charged. In a nonpolar bond, electrons are shared equally.
Question: What causes bonds to be polar or nonpolar?
1. Observe: Select the Show polar molecule inset checkbox. The animation shows the
probable location of electrons (orange dots) in a polar molecule.
A. What do you notice about the distribution of the electrons?
B. How does this electron distribution affect the charges of the bonded atoms?
2. Observe: Turn on the Show nonpolar molecule inset.
A. How are the electrons in this molecule distributed?
B. Why do the bonded atoms remain neutral?
3. Experiment: Turn off Show polar molecule inset and Show nonpolar molecule inset.
Check that Show valence electrons is turned on. Drag the Na and Cl atoms into the
simulation area. Click Play. Note the colors. Red indicates a negative charge, while blue
indicates a positive charge.
A. Does a polar or nonpolar bond form?
B. Try several other metal/nonmetal combinations. What do you notice about the bonds
that form?
Ionic bonds are polar bonds that form between metal and nonmetal atoms. In this
bond, valence electrons are transferred from a metal to a nonmetal. Drag each of
these metal/nonmetal combinations into the Ionic bond bin on the upper right.
(Activity A continued on next page)
Student Exploration: Polarity and Intermolecular Forces
Vocabulary: dipole, dipole-dipole force, dipole-induced dipole force, electronegativity,
intermolecular force, ionic bond, London dispersion force, molecule, nonpolar, nonpolar
covalent bond, partial charges, polar, polar covalent bond, valence electron
Prior Knowledge Questions (Do these BEFORE
using the Gizmo.)
1. A big bully is having a tug-of-war with a small child.
There is a ball attached to the middle of the rope.
Toward whom will the ball move?
2. Two equally strong kids are having a tug-of-war. What do you expect to happen to the ball in
this situation?
Gizmo Warm-up
Just like in a tug-of-war, atoms that are bonded to one another pull
on the electrons they share. In the Polarity and Intermolecular
Forces Gizmo, you will explore how these opposing forces relate to
bond types and the forces between molecules.
To begin, drag the Na (sodium) and Cl (chlorine) atoms into the simulation area. Turn on Show
valence electrons. A valence electron is found in the outermost energy level of the atom.
1. Click Play ( ). What do you notice?
2. Which atom seems to be pulling more on the sodium’s one valence electron?
How do you know?
3. What happens to the colors of the simulated atoms, and what does this indicate?
, Get the Gizmo ready:
Activity A:
On the BOND POLARITY tab, click Reset ( ).
Bond polarity
Drag the atoms out of the simulation area.
Introduction: A neutral atom has the same number of protons as electrons. Atoms that gain
electrons become negatively charged, while those that lose electrons become positive. A polar
bond forms when shared electrons are pulled closer to one atom than another, causing the
bonded atoms to become partially charged. In a nonpolar bond, electrons are shared equally.
Question: What causes bonds to be polar or nonpolar?
1. Observe: Select the Show polar molecule inset checkbox. The animation shows the
probable location of electrons (orange dots) in a polar molecule.
A. What do you notice about the distribution of the electrons?
B. How does this electron distribution affect the charges of the bonded atoms?
2. Observe: Turn on the Show nonpolar molecule inset.
A. How are the electrons in this molecule distributed?
B. Why do the bonded atoms remain neutral?
3. Experiment: Turn off Show polar molecule inset and Show nonpolar molecule inset.
Check that Show valence electrons is turned on. Drag the Na and Cl atoms into the
simulation area. Click Play. Note the colors. Red indicates a negative charge, while blue
indicates a positive charge.
A. Does a polar or nonpolar bond form?
B. Try several other metal/nonmetal combinations. What do you notice about the bonds
that form?
Ionic bonds are polar bonds that form between metal and nonmetal atoms. In this
bond, valence electrons are transferred from a metal to a nonmetal. Drag each of
these metal/nonmetal combinations into the Ionic bond bin on the upper right.
(Activity A continued on next page)
