Simulations & Videos for

Lesson 6.12: Natural Resources & Synthetic Materials

Natural Resource Used to Make the Gel Worm – Sodium Alginate

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

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

Both models show:

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

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.