restsclub.blogg.se - 99 invisible invisible women lesson plan

Objective: Create a paper boat capable of floating in water using crayons.Ĭompetition Variations: Place the boats in a long container of water and race them. Remember, color change is one of the results of a chemical reaction. The acidic grape juice undergoes a chemical reaction with the alkaline (basic) baking soda to produce a different color, making the secret message appear.

How do the properties of acids and bases explain being able to see the “invisible ink”?.

What, in this activity, is the acid and what is the base? Were you correct?.

To read the “secret message” paint grape juice across the paper with a brush/sponge.

Write a message/draw on the white paper.

Dip the Q-tip or brush into the mixture.

Mix baking soda and water in equal quantities (¼ cup of each) in a bowl or cup.

What do you think will happen when and acid and base are combined?.

Soap), tasting bitter, and releasing OH -ions (pronounced hydroxide ions). Basic properties include being slippery to the touch (ex.

Grape Juice (concentrate recommended the darker the better)Ī base is a chemical substance with a pH of more than 7.

Any acidic liquid works: orange juice, milk, vinegar, etc. The writing turns brown because the acid weakens the paper, and, when heat is applied, the acidic areas burn faster. Diluting the lemon juice in water gives it the “invisible” quality when applied to the paper. Lemon juice oxidizes (reacts with oxygen) and turns brown when heated. What happened, chemically, that allowed us to see the previously invisible message?.

When dry and the kids are ready to view their messages, heat the paper by placing it under a heat lamp, over an open flame with adult supervision, or in direct sunlight (95 degrees+).Wait for the paper to dry until the “ink” becomes invisible.Dip the Q-tip into the mixture and have the kids write/draw on the white paper.Add a few drops of water to dilute it.Juice the lemon (kids like helping with this step) and capture the juice in a bowl.What do you think will happen when lemon juice is exposed to the sunlight?.How do you think sunlight will play a factor in revealing your invisible message?.Its properties include dissolving/ corroding metals, tasting sour, and giving off positive Hydrogen ions.Ĭommon answers: sour, acidic, corrode your teeth, taste good A physical change is a change in texture, state (solid, liquid, gas), volume, weight, etc.Īn acid is a chemical substance that has a pH value of less than 7. What is the difference between a chemical and a physical change?Ī chemical reaction takes place when one or more of the following occur: a gas is produced, the temperature changes, a solid is formed, or a color change occurs.Preferably a heat lamp or small flame if accessible (Intense sunlight works in theory, but best when 95 degree +).Materials ($5~25 depending on your method of heat) Objective: To investigate the chemical reactions behind making invisible ink with: