• Amphibians are cold-blooded vertebrates (their body temperature changes with the environment).

• They live both in water and on land during different stages of their life.

• Examples: frogs, toads, salamanders, newts.

Features of Amphibians:

• Skin: Moist, thin, and soft; used for breathing (through skin) and sometimes protection.

• Respiration: Can breathe through gills (as young tadpoles) and lungs (as adults).

Metals and non-metals show many differences when compared, especially in living organisms and their surroundings. Metals are usually hard, shiny, and have the ability to be shaped without breaking, which is called malleability. They can conduct heat and electricity very well, making them useful in wires and machines. Non-metals, on the other hand, are usually soft or brittle and do not shine like metals. They are poor conductors of heat and electricity. While metals tend to lose electrons in reactions, non-metals usually gain electrons, forming negative ions. Metals form basic oxides when they react with oxygen, but non-metals form acidic oxides. Important non-metals like oxygen are essential for life because all living beings need oxygen to survive. Non-metals such as nitrogen and phosphorus help plants grow as fertilizers, and chlorine is used to clean water. Overall, metals are strong and good for construction and tools, while non-metals play vital roles…

An atom's structure consists of a dense, positively charged nucleus at the center, made of protons and neutrons, and negatively charged electrons orbiting the nucleus in shells or orbitals. The number of protons in the nucleus determines the element's atomic number, while a neutral atom has an equal number of protons and electrons. Electrons exist in specific energy levels, governed by quantum mechanics, and their arrangement determines the atom's chemical properties.

Adaptations of Arabian Oryx (Desert Habitat)

White body colour reflects sunlight → keeps the body cool in the desert.

Can survive many days without drinking water → gets water from plants + reduces water loss.

Body temperature can rise safely → less sweating → saves water.

Long sharp horns → protection from predators.

Wide hooves → easy to walk and run on loose desert sand.

• The human skeletal system is made of 206 bones.

• It gives the body shape and support.

• It protects important organs like the brain, heart, and lungs.

• It works with muscles to help the body move.

• Bones store minerals such as calcium.

• Bone marrow inside some bones makes blood cells.

Burning releases exothermic reaction

An exothermic reaction is a chemical or physical process that releases energy, typically as heat, light, or sound, into its surroundings.

A chemical bond is the attractive force that holds atoms, ions, or molecules together to form a compound.

An attractive force is a force that causes objects or particles to move toward each other.

Combustion is a rapid chemical reaction between a substance, called a fuel, and an oxidant, usually oxygen, that releases energy as heat and light, often with a flame.

An oxidant, also called an oxidizing agent, is a chemical substance that accepts electrons from another substance during a chemical reaction.

1. air pollution

air pollution happens when harmful gases dust or smoke mix with the air we breathe

2. water pollution

water pollution happens when dirty or harmful substances mix into water bodies like rivers lakes and oceans

3. land pollution

Land pollution happens when the ground is covered or filled with harmful waste

1. Meaning:Variation means small difference in a species.

   
   

2. Example: All humans are the same species, but we are differ in skin type, hair colour, height etc.

   
   

3. Cause: Variation happens because of the genes.

   
   

4. Types:

   1. Inherited variantion

   2. Environmental Variation