Science Revision Notes PDF

# Science Notes ## Lesson 1: Physical Change - **What is a physical change?** A physical change is to change one or more physical properties in which the matter's identity stays the same. - **Examples of physical changes:** - Breaking glass - Mixing candies - Shredding paper - Fold...

# Science Notes ## Lesson 1: Physical Change - **What is a physical change?** A physical change is to change one or more physical properties in which the matter's identity stays the same. - **Examples of physical changes:** - Breaking glass - Mixing candies - Shredding paper - Folding paper - Melting ice - **Question and answer:** - **Which of the following is not a physical change?** - Water turns into ice (physical change) - Baking cake (chemical change) - Frying an egg (chemical change) - Burning a match (chemical change) - **What is involved in getting matter to change state?** Transferring energy to or from a substance can change its state. A form of energy is thermal energy. - **What does thermal mean?** It means heat. - **How can the state of matter be changed?** - From solid to liquid: melting - From liquid to gas: evaporation - From liquid to solid: freezing ## Lesson 2: Chemical Change - **What is a chemical change?** A change in matter in which the substance changes into new substances with new chemical physical properties. - **What are the signs of a chemical change?** - Change in color - Change in odor ## Lesson 3: Mixtures - **What is a mixture?** A mixture is a matter that can vary in composition. - **Types of mixtures:** - **Heterogeneous:** A type of mixture in which the substances are not evenly mixed (fruit salad). - **Homogeneous:** A type of mixture in which the individual substances are evenly mixed (tea with sugar). - **Separating mixtures:** - **Mechanical separation:** Often using hands. - **Filtration:** A screen or paper that lets the liquid particles through but traps the solid particles. - **Evaporation:** Vaporizing a liquid and leaving the dissolved solid behind. This separates salt solutions. - **Magnetism:** Magnetic separation. - **Separation funnel:** A piece of laboratory glassware used in liquid-liquid extractions to separate the components. - **Distillation:** The separation of a mixture of liquids based on the physical property of boiling point. ## Lesson 4: Interactions within an Ecosystem - **What is an ecosystem?** All the living and nonliving things and how they interact in a given area make up an ecosystem. - **What is the biosphere?** All of the ecosystems on Earth make up the biosphere. - **What is the biosphere?** Is the parts of Earth and the surrounding atmosphere where there is life. - **What are populations?** All the organisms of the same species that live in the same area at the same time. - **What are species?** A group of organisms that have similar traits and are able to produce fertile offspring. - **What is a community?** All the populations of different species that live together in the same area at the same time. - **What is the difference between an ecosystem and a community?** - An ecosystem is all the living and nonliving things and how they interact in a given area. - A community is a group of different species that live together in the same area. - **What is a limiting factor?** A limiting factor is anything that restricts the size of a population. - **What is biotic potential?** Biotic potential is the potential growth of a population if it could grow in perfect conditions with no limiting factors. - **What is carrying capacity?** Carrying capacity is the largest number of individuals of one species that an ecosystem can support overtime. - **What is overpopulation?** Overpopulation is when a population size grows so large that it causes damage to the environment. - **Question and answer:** - **What are the problems that can be caused by overpopulation?** Overpopulation of birds eats spiders and can cause damage to a spider population. - **What is a symbiotic relationship?** Symbiotic relationships occur when two organisms live in indirect contact and form a relationship. - **What are the types of symbiotic relationships?** - **Commensalism:** A symbiotic relationship that benefits one species but does not harm or benefit the other. - **Parasitism:** A symbiotic relationship that benefits one species and harms the other. The species that benefits is the parasite, and the species that is harmed is the host. - **Mutualism:** A symbiotic relationship in which both partners benefit. - **What are cooperative relationships?** Cooperative relationships can be found in many different populations across the world. - **What are predator-prey relationships?** Predator-prey relationships are one in which one organism, the predator, eats another organism, the prey. - **Can this relationship be positive?** Yes, predators help to prevent prey populations from growing too large for the carrying capacity of the ecosystems and keep the prey population healthy. - **What are competitive relationships?** Competitive relationships are interactions between two or more organisms that need the same resource at the same time. ## Lesson 5: Resources in an Ecosystem - **What are biotic factors?** Biotic factors are living things, such as: - Animals - People - Plants - **What are abiotic factors?** Abiotic factors are nonliving things, such as: - Sun - Water - Soil - Rocks ## Lesson 6: Chemical Properties - **What is a chemical reaction?** A chemical reaction is a process that produces one or more substances that are different from the original substances. - **What are products?** Products are any new substance formed during a chemical reaction. - **What are reactants?** Reactants are substances that are present before the chemical reaction. - **What is a chemical property?** A characteristic that can be observed when matter changes into a different type of matter. - **Question and answer:** - **What are the physical and chemical properties of ash and wood?** - **Ash:** - Physical property: White powder - Chemical property: Doesn't react with oxygen - **Wood:** - Physical property: Hard brownish solid - Chemical property: Reacts with oxygen - **What are the signs of a chemical change?** - Warming or cooling - Formation of bubbles - Formation of precipitate - Release of light - **What is a chemical reaction in terms of substances?** A chemical reaction is a process that produces one or more substances that are different from the original substances.