Engines and Vehicles

    

                                                      Engines and Vehicles

When you see a jet plane sweeping through the sky or watch a car swimming past, powerful engines are racing inside them. Most vehicles are powered by engines machines that burn fuel to let heat out. Even tiny amounts of energy when they burn. An engine turns this heat energy into kinetic energy.

Air

All around us in an invisible mixture of gases we call air. It contains about 15 different gases, although most of it is just two. Nitrogen and Oxygen. The exact content of air varies from place to place. For example, damp air has more water vapor than dry air.

Acids and Bases

Liquid substances have a level of acidic property that describes how they react to other substances. At the opposite end of this scale, acids and bases are made by dissolving particular substances in water. At their strongest they can be very dangerous, eating away metals and other solids and causing burns if they touch human skin.

1. Battery acid
2. Vinegar
3. Lemon Juice
4. Orange Juice
5. Tomato Juice
6. Cow milk
7. water
8. Toothpaste
9. Antacid tablet
10. Cement
11. Drain cleaner.

Classifying life

Scientists estimate that there are as many as 9 million species of life on earth. More than 6 million of these are yet to be discovered. There are million of different types of living things on earth. To understand how they relate to each other, scientists arrange them into groups. This is called classification. Some groups are easy to identify , for example, all mammals feed their young ones milk, but other are more complicated.

List:
1. Microlife
2. Fungi
3. Plants
4. Invertebrates
5. Vertebrates

Vertabrates

Only about 4 percent of animal species are vertebrates. The rest are invertebrates. The number of vertebral bones varies from fewer than 10 in frogs to more than 70 in the deep-sea snipe eel.

1. Fish - regal tang
2. amphibians - poison dart frog
3. reptiles - savana monitor lizard
4. birds - pigeon
5. mammals - black panther

Invertabrates

They don't have backbone. The biggest one is the deep sea colossal squid.

Insect biggest groups.

1. Sponges

2. mollusks

3. Jellyfish

4. Insects

5. starfish

6. spiders and scorpions

7. worms

8. crustaceans

9. centipedes and millipedes