Ten scientific facts your child needs to know

Did humans live with dinosaurs? Does the moon disappear in the day? Kids love to know the answers to life's mysteries but there are a few facts they often get wrong in the name of science.

1. Dinosaurs and cavemen did not live at the same time

People did not coexist with the dinosaurs. Dinosaurs and people are well separated in terms of geologic time. Humans evolved about 65 million years after dinosaurs became extinct.

2. Batteries don't have electricity inside them

Chemical energy is stored in a battery; a chemical reaction converts the chemical energy to electricity. At the centre of each dry cell battery is a rod called a cathode, which is generally made of metal or graphite and is surrounded by an electrolyte paste. When a load is connected to the battery's terminals, a chemical reaction occurs between the cathode and the paste in each cell to produce about 1.5 volts of electricity.

3. The Moon cannot only be seen at night

The Moon can be seen in the daytime depending on its position relative to the Earth and the Sun. During the day, the Moon will appear white or grey because of the sunlight it reflects.

4. Rain doesn't come from holes in clouds

The clouds floating overhead contain water vapour and cloud droplets, which are small drops of condensed water. These droplets are too small to fall as rain, but they are large enough to be seen as clouds. Water is continually evaporating and condensing in the sky. The water droplets grow as a result of continued condensation and collision of the water particles. When enough collisions occur, they produce droplets and the droplets fall out of the cloud as rain.

5. The Sun doesn't boil the sea to create water vapour

Heat energy is used to break the bonds that hold water molecules together; water evaporates easily at the boiling point (100°C) but evaporates much slower at the freezing point (0°C). Water does not need to boil for evaporation to occur.

6. Objects don't float in water because they're lighter than water

An object will float if it weighs the same as or less than the weight of the water it displaces.

7. Heat is energy

Heat is a form of energy: the heat energy of a substance is determined by how active its atoms and molecules are. A hot object is one where the atoms and molecules are excited and show rapid movement. A cooler object's molecules and atoms will be less excited and show less movement.

8. The Sun doesn't disappear at night

The Earth is a large sphere that is spinning. The Sun's light shines on the Earth all the time; the side of the Earth that is facing the Sun will experience daylight. As the Earth keeps spinning, the side that was in the sunlight turns away from the Sun and enters the Earth's shadow to experience night.

9. The Sun is a star

The Sun is the star at the centre of the Solar System. It has a diameter of about 1,392,000 kilometres – about 109 times that of the Earth.

10. The Sun is not smaller than the Earth

The Sun appears smaller in size when seen from Earth because of the long distance between the Sun and the Earth. The radius of the Sun is actually 109 times larger than the Earth and the volume of the Sun is about 1,000,000 times that of Earth.