Skip Navigation

Chapter 4, Lesson 5 Multimedia

Sodium and Chlorine React

A small piece of sodium metal is carefully inserted into a flask of chlorine gas. They react violently when one drop of water is added to the reacts through a narrow glass tube.

Get Adobe Flash player

©Journal of Chemical Education, Chemistry Comes Alive Logo

  • A small piece of sodium metal is placed in a flask of chlorine gas.
  • A little water helps expose the sodium so it can react with the chlorine gas.
  • The reaction releases a lot of heat as the ionic compound sodium chloride is formed. The demonstration shown in this video is very dangerous. Do not attempt to perform this demonstration.

Ionic Bond in Sodium Chloride

The process of ionic bonding between a sodium atom and an chlorine atom. The sodium atom donates an electron to the chlorine atom. The two oppositely charged ions then attract one another.

Get Adobe Flash player

  • A sodium and chlorine atom are near each other.
  • An electron from each atom feel the attraction from the other atom's nucleus.
  • The attraction by chlorine is stronger than the attraction by sodium.
  • An electron is transferred from sodium to chlorine. Sodium becomes a positive ion and chlorine becomes a negative ion.
  • The positive and negative ions attract each other and form the ionic compound sodium chloride.

Ionic Bond in Sodium Chloride

A sodium and a chlorine atom near each other.The outermost electron of the sodium atom feels an attraction for the protons in the nucleus of the chlorine atom. A sodium atom donates an electron to the chlorine atom.
  • A sodium and chlorine atom are near each other.
  • An electron from each atom feel the attraction from the other atom's nucleus.
  • The attraction by chlorine is stronger than the attraction by sodium.
  • An electron is transferred from sodium to chlorine.Sodium becomes a positive ion and chlorine becomes a negative ion.
  • Positive and negative ions attract each other and form an ionic bond and the compound sodium chloride.

Sodium Chloride Crystal

A detailed look at a sodium chloride crystal. The ions are arranged in a regular repeating pattern in the form of a cube.

Get Adobe Flash player

The sodium chloride crystal is made up of alternating sodium and chloride ions. This video appears courtesy of Roy Tasker.
© Roy Tasker, VisChem Project.

Cubic Sodium Chloride

Salt crystals magnified one hundred times under a microscope.

When salt crystals are examined closely under a microscope, their cubic shape becomes clear.

Calcium Chloride Ion

The process of bonding in calcium chloride. A calcium atom donates one electron to two chlorine atoms, forming oppositely charged ions. The ions are then attracted to one another.

Get Adobe Flash player

  • One calcium and two chlorine atoms are near each other.
  • An electron from each atom feel the attraction from the other atom's nucleus.
  • The attraction by the chlorine atoms is stronger than the attraction by the calcium atom.
  • Two electrons are transferred from the calcium atom, one to each chlorine atom.
  • Calcium becomes a +2 ion and each chlorine becomes a -1 ion. The +2 calcium ion and the two -1 chloride ions attract each other and form an ionic bond and the compound calcium chloride.

Calcium Chloride Ion

Two chlorine atoms and a calcium atom near each other.The two outermost electrons of the calcium atom feel an attraction for the protons in the nucleus of the chlorine atom. The calcium atom donates one electron to each of the chlorine atoms.
  • One calcium and two chlorine atoms are near each other.
  • An electron from each atom feel the attraction from the other atom's nucleus.
  • The attraction by the chlorine atoms is stronger than the attraction by the calcium atom.
  • Two electrons are transferred from the calcium atom, one to each chlorine atom. Calcium becomes a +2 ion and each chlorine becomes a -1 ion.
  • The +2 calcium ion and the two -1 chloride ions attract each other and form an ionic bond and the compound calcium chloride.