Here it is– a sneak peak at my next book: EAT YOUR SCIENCE HOMEWORK: RECIPES FOR INQUIRING MINDS
Okay, so it won’t be out for another year, but here is a bonus section on volcanoes. Look back for part 2 next week!
Lava—love it or leave it? The word lava comes from an Italian word that means a stream formed as a result of pouring rain. When lava, or liquid rock, erupts from a volcano, it flows down the sides of a volcano as if it were water. Just how hot does rock have to get before it turns into lava? Normal lava is between 1382° to 2282° Fahrenheit (750° to 1250° Celsius). To bake a pizza, you would use a hot oven, but even a hot oven is only about 425° Fahrenheit!
Scientists can tell the approximate temperature of lava by looking at what color it is. Orange to yellow is more than 1650° F (900° C). Bright, dark red is about 1165° F (630° C), and light red is around 895° F (480° C). That lava is hot stuff!
Volcanoes are formed from cooled lava. There are many active volcanoes in the world today. In the United States, two of them are found in Hawaii. The first, Mauna Loa, is the largest volcano in the world, rising four kilometers above sea level. It last erupted in 1984. Another volcano, Kilauea, is one of the world’s most active volcanoes. It started its eruptions in 1983 and has been continually erupting since then. Worldwide, about fifty to seventy volcanoes erupt every year (Plus, there are more on the ocean floor that we can’t see). That’s lots of lava!
Science Sampler—Fond of Fondue?
The idea of melting cheese and dipping bread in it probably came from peasants in Switzerland and France, who needed a tasty way to eat hardened cheese and stale bread. Nowadays, fondues can also be made with chocolate for dipping.
Which has a lower melting point: cheese or chocolate?
Make a hypothesis.
Take an equal portion of cheese and chocolate. Place the cheese in a microwave that has a glass viewing window. Turn the microwave on and watch carefully. At the first sign of melting, turn the microwave off and record how long it took. Repeat the experiment with the chocolate.
Observe and analyze.
What did you learn? (Now, dip a pretzel or piece of croissant into the melted chocolate or cheese for your own mini-fondue. What a treat!)
The why of things: Substances undergo change. A chemical change cannot be reversed because the structure of the molecules has been permanently changed (cake dough to baked cake).
In a physical change, a substance can be changed back to its original state (solid chocolate to melted chocolate and back to solid chocolate).