Making your own rainbow

A cool ex­per­i­ment to per­form with your child – min­i­mum ef­fort, max­i­mum emo­tions!

Safe­ty pre­cau­tions

None.

Equip­ment

• sweet dragée;
• white plate;
• wa­ter.

Step-by-step in­struc­tions

Ar­range some dragée (we opt­ed for Skit­tles) along the con­tour of a white plate. Add enough wa­ter to im­merse the bot­tom half of the can­dies. In a few min­utes, a rain­bow will ap­pear on the plate! Try dif­fer­ent dragée com­bi­na­tions, such as ar­rang­ing them in a checker­board pat­tern.

Process de­scrip­tion

Dragée are coat­ed with sug­ar glaze and food col­or­ing, which dis­solve eas­i­ly in wa­ter to form col­ored sug­ar so­lu­tions. These sug­ar so­lu­tions are denser than wa­ter. Due to their greater den­si­ty, the col­or­ful so­lu­tions sink to the bot­tom of the plate and tend to dis­place any non-sug­ary wa­ter. This cre­ates a col­or­ful “cur­rent” at the base of the plate. Since the den­si­ties of all the col­ored so­lu­tions are ap­prox­i­mate­ly the same, the col­ors don’t mix, in­stead flow­ing along the bot­tom to the cen­ter in even lines! The col­ors will lat­er mix due to dif­fu­sion – a much slow­er process than the sep­a­ra­tion of sug­ar so­lu­tions and pure wa­ter.