Skip Navigation

Chapter 6, Lesson 12 Multimedia

Natural resource used to make the gel worm
Sodium alginate

Brown Seaweed

Sodium alginate is made from brown seaweed

The harvested seaweed is:

  • Cut and mixed with water to make a thick gel
  • Diluted with more water and filtered
  • Mixture evaporated and further processed to make sodium alginate powder

Natural resource used to make the gel worm
Calcium chloride

Limestone

Calcium chloride is made from limestone, which is calcium carbonate.

  • Limestone is a sedimentary rock, formed from the shells and skeletons of ancient sea creatures.
  • The mined limestone is reacted with hydrochloric acid or sodium chloride to make the calcium chloride

Sodium alginate polymer

Sodium Alginate

Both models show:

  • Sodium ion has a positive charge
  • Place where it's bonded to the molecule has a negative charge

Crosslinking sodium alginate

Crosslinking Sodium Alginate
  • Calcium ions have two positive charges
  • Calcium ions bond to two sodium alginate molecules crosslinking the chains
  • Many crosslinking connections make the sodium alginate thicken to become a gel