Why carbon dioxide is used as fire extinguisher

Carbon dioxide (CO₂) is not a supporter of combustion (combustion is an exothermic process that involves the formation of heat and light ).

Fire is caused by the three elements i.e. fuel, oxygen, and heat. If one of the three elements is removed fire will stop.Carbon dioxide removes one element, i.e oxygen.

(CO₂)​, being heavier than oxygen, covers the fire like a blanket. Since the contact between the fuel and oxygen is cut off, the fire is controlled.

Ice is in the solid state. When heated, it melts into the liquid state (water) and which (water) when further heated vapourizes.

For a physical change, no new substance(s) are formed and the change is reversible. The sugar can be separated from the water by means of distillation and therefore reversible.

Kinetic energy is the energy a body possesses by virtue of its motion.

Potential Energy = Mass x Acceleration due to gravity x Height
Mass = 50 kg
Acceleration due to gravity = 10 ms^-2
Height = 5 m
Potential Energy = 50 x 5 x 10 J
Potential Energy = 2500 J

Materials like glass and plastic are poor electrical conductors, and are called insulators. They are used to stop electricity from flowing where it is not needed or where it can be dangerous, such as through our bodies. Cables are wires covered in plastic so we can handle them safely.

Tapeworm

Tapeworms (taeniasis) are a type of parasite that live in the intestines of animals.

Humans can become infected by eating or drinking tapeworm eggs or larvae (immature tapeworms) in contaminated meat or water.

Dracunculiasis is an infection caused by a parasite called the Guinea worm. A person becomes infected when they drink contaminated water.

Usually the disease has no initial symptoms. About one year later, there is a painful burning feeling as a blister forms, usually on the legs. The blister bursts as the worm then comes out of the skin over a few weeks.

The worm can be pulled out a few centimetres each day. The process usually takes weeks.

Types of feedings

Carnivore: the eating of animals.

Herbivore: the eating of plants.

Omnivore: the eating of both plants, animals, fungi, bacteria etc.

Importance of crop rotation

1. Increases soil fertility/Adds nitrogen to soil
2. Enhances soil structure
3. Prevents soil erosion
4. Improves soil nutrients and nutrient uptake regulation
5. Controls the spread of pests and diseases
6. Controls weed easily
7. There is effective use of the land
8. Harvest of different types of crops on the same piece of land

Equation of photosynthesis

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.

This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products.

Bile is a fluid that is made and released by the liver and stored in the gallbladder. Bile helps with digestion. It breaks down fats into fatty acids, which can be taken into the body by the digestive tract.

Anemometer: Wind speed
Barometer: Atmospheric pressure
Hygrometer: Relative humidity
Manometer: Pressure acting on a column of fluid