SCIENCE REVISION FOR TEST PDF

SCIENCE REVISION FOR TEST BONDING AND REACTIONS 1. Describe the current model of the structure of the atom (draw labelled diagram/modelling activity). 2. Relate mass number and atomic number to proton, neutron and electron numbers and arrangements. Mass Number: Total number of...

SCIENCE REVISION FOR TEST BONDING AND REACTIONS 1. Describe the current model of the structure of the atom (draw labelled diagram/modelling activity). 2. Relate mass number and atomic number to proton, neutron and electron numbers and arrangements. Mass Number: Total number of protons and neutrons in the nucleus. Atomic Number: Number of protons in the nucleus, which equals the number of electrons in a neutral atom. Protons: Protons are in the nucleus and equal the atomic number. The mass number is protons plus neutrons. Neutrons: Calculated by subtracting the atomic number from the mass number (Neutrons = Mass number - atomic number) Electrons: Electrons: In a neutral atom, the number of electrons equals the atomic number, which is the same as the number of protons. If the atom gains or loses electrons, it becomes an ion. 3. Explain periodic patterns using periods and groups (metal/nonmetals/metalloids, noble gases, valencies). - Periods: Horizontal rows showing the number of electron shells. - Groups: Vertical columns with elements sharing the same outer electron count, leading to similar properties. - Metals: Left and center (groups 1-12). - Nonmetals: Right side (groups 14-18). - Metalloids: Between metals and nonmetals, with mixed properties. - Noble Gases: Group 18, non-reactive due to full outer electron shells.  4. Describe types of chemical bonds including ionic, covalent and metallic bonds (how they occur e.g. electron sharing, transfer and properties of each bond type) Ionic - - metal and one or more nonmetals. - Form when positive metal ions (cations) are attracted to negative non-metal ions (anions). - Lose or gain electrons makes it a positive or negative ion Covalent - - Made up of 2 or more different non-metals - Forms because outer shells of individual elements that are not full - Sharing of electron Metallic - - Metal atoms release electrons, creating a "sea of electrons" around positive ions, holding them together. - Properties: Conductivity: Good at conducting heat and electricity Malleability/Ductility: Can be shaped without breaking Lustre: Shiny due to reflecting light Strength: Strong bonds, making the metals tough High melting/ Boiling points: Requires a lot of heat to melt or boil 7. Explain how ionic compounds form in relation to the formation of anions and cations, and the donating and receiving of electrons to complete the valence shell of electrons. Ionic compounds form when a metal donates one or more electrons to a nonmetal. This transfer creates a positive ion (cation) and a negative ion (anion), which are held together by electrostatic attraction. The metal typically loses electrons to complete its valence shell, while the nonmetal gains electrons to complete its shell. 8. Construct chemical formulas of some common ionic compounds: i. Monatomic Ionic Compounds: Sodium chloride (NaCl): Sodium ion (Na⁺) + Chloride ion (Cl⁻) Magnesium oxide (MgO): Magnesium ion (Mg²⁺) + Oxide ion (O²⁻) Calcium fluoride (CaF₂): Calcium ion (Ca²⁺) + Fluoride ion (F⁻) Aluminium bromide (AlBr₃): Aluminium ion (Al³⁺) + Bromide ion (Br⁻) Potassium iodide (KI): Potassium ion (K⁺) + Iodide ion (I⁻)  ii. Polyatomic Ionic Compounds: Sodium nitrate (NaNO₃): Sodium ion (Na⁺) + Nitrate ion (NO₃⁻) Calcium sulfate (CaSO₄): Calcium ion (Ca²⁺) + Sulfate ion (SO₄²⁻) Aluminium phosphate (AlPO₄): Aluminium ion (Al³⁺) + Phosphate ion (PO₄³⁻) Magnesium carbonate (MgCO₃): Magnesium ion (Mg²⁺) + Carbonate ion (CO₃²⁻) Potassium hydroxide (KOH): Potassium ion (K⁺) + Hydroxide ion (OH⁻) Calcium acetate (Ca(CH₃COO)₂): Calcium ion (Ca²⁺) + Acetate ion (CH₃COO⁻) 9. Explain how covalent compounds form in relation to the sharing of electrons to complete the valence shell of electrons Covalent compounds form when atoms share pairs of electrons to complete their valence shell. This occurs between nonmetals, where both atoms need electrons to achieve a stable configuration. 10. Construct chemical formulas of some common covalent compounds, eg Carbon Dioxide, Water, Methane Carbon Dioxide: CO₂ Water: H₂O Methane: CH₄ Ammonia: NH₃ Oxygen Gas: O₂ Nitrogen Gas: N₂ Hydrogen Chloride: HCl Glucose: C₆H₁₂O₆ 11. Recap reactants, products and how to write and balanced chemical equations (including states of matter) A chemical equation represents a reaction where reactants transform into products. To balance the equation, ensure the number of atoms of each element is equal on both sides. 2H2​+O2​→2H2​O or 2H2​O ​→ 2H2​+O2 12. Define decomposition and write basic chemical reactions to show a variety of decomposition reactions e.g. electrolysis of water A decomposition reaction occurs when a single compound breaks down into two or more simpler substances. 2H2​O→2H2​+O2​ 13. Define the following reaction types and write chemical equations to show the products and reactants of these reactions. Precipitation, combustion, corrosion Precipitation: A solid (precipitate) forms when two solutions are mixed. AgNO3​+NaCl→AgCl (s)+NaNO3​ Combustion: A substance reacts with oxygen, releasing energy. CH4​+2O2​→CO2​+2H2​O Corrosion: A metal reacts with its environment, leading to degradation. 4Fe+3O2​→2Fe2​O3​ 14. Explain the difference between endothermic and exothermic reactions Endothermic: Absorbs energy from the surroundings (e.g., melting ice). Exothermic: Releases energy to the surroundings (e.g., combustion). NUCLEAR CHEMISTRY 15. Define radioactivity as types of matter of emitting energy and subatomic particles spontaneously Radioactivity is when unstable atoms release energy and particles (like alpha, beta, or gamma rays) to become stable. 16. Describe the conditions that cause a nucleus to be unstable - e.g extra neutrons or protons in the nucleus. A nucleus becomes unstable if it has too many neutrons or protons. It can also be unstable if it is too big, leading to radioactive decay. 17. Represent alpha and beta reactions as nuclear decay equations. - Alpha Decay: The nucleus loses 2 protons and 2 neutrons (an alpha particle) - Beta Decay: A neutron turns into a proton and an electron (the beta particle is emitted)  18. Identify the half life of a radioactive isotope as the time taken for half of the atoms in a sample to undergo radioactive decay - Half-life is the time it takes for half of a radioactive sample to decay. 19. Evaluate the impact on society of using radioisotopes in medicine, industry and environmental monitoring - Medicine: Used in scans and cancer treatments. - Industry: Used to check for cracks in materials. - Environment: Help monitor pollution and track processes in nature. 20. Describe nuclear fission and nuclear fusion - Fission: Splitting a big atom to release energy (used in nuclear reactors). - Fusion: Combining small atoms to make a bigger one, releasing energy (happens in stars). 21. Outline the range of impacts (e.g. environmental, social, economic, ethical, political) of nuclear reactions, including the raw materials used, the various stages of production and nuclear waste - Environmental: Nuclear waste and accidents can harm the environment. - Social: Nuclear power provides energy but comes with safety concerns. - Economic: Nuclear energy can be cost-efficient but expensive to set up. - Ethical: Issues about safety and fairness arise with nuclear energy. - Political: Nuclear weapons and energy affect international relations. PHYSICS LEARNING INTENTIONS Learning intentions: 1. Define the terms ‘distance’ and ‘displacement’ in relation to motion Distance ( km, m , cm, mm) - Refers to how much ground you cover Displacement - Going the shortest distance from point A to B Eg. Imagine you take the same route everyday from your house to the cafe. Some days you take the route along the roads and other days you cut through the park. It doesn’t matter which route you take because you're still getting to the same place. If you cut through the part it is 1.7km which is displacement and if you go along the roads your distance is 2.4km. 2.Explain the difference between scalar and vector measurements Scalar: A quantity that has only magnitude (e.g speed, distance, time, mass). Vector: A quantity that has both magnitude and direction (e.g velocity, displacement, force).  3. Calculate speed, time and distance using formula v=d/t Formula - V= D/T where: V- Speed D- Distance T- Time 4. Define velocity and compare it to speed Speed: The rate at which an object covers distance (scalar). Velocity: Speed in a specific direction (vector). 5. Draw and interpret distance (and displacement) time graphs A distance-time graph shows how far an object travels over time, where the slope of the line represents speed. A displacement-time graph shows the change in position over time, and the slope represents velocity. 6. Use distance time graphs to determine speed of an object The slope (rise over run) of a distance-time graph gives the speed of the object. 7. Define acceleration as the change in speed over a period of time Defined as the rate of change of velocity over time: Formula: a=Δv/ T , where: ○ a = acceleration ○ Δv = change in velocity (Final Velocity Vf - Initial velocity Vi) ○ t = time taken for the change 8. Calculate acceleration using the equation Acceleration = Final Speed - Initial Speed / Time Taken Formula: a = Vf - Vi / T 9. Interpret ticker timer tape to determine the motion of an object  The spacing between dots on a ticker timer tape represents motion. Equally spaced dots indicate constant speed, while increasing or decreasing spaces indicate acceleration or deceleration. 10. Review the types of forces that can act on an object (contact and non-contact forces including examples of each). Contact forces: Forces that occur when objects physically interact (e.g., friction, tension). Non-contact forces: Forces that act without physical contact (e.g., gravity, magnetic force). 11. Draw force diagrams and determine the effect of balanced and unbalanced forces acting on moving and stationary objects 12. Compare the definitions of weight and mass (mass is the amount of matter in a material, while weight is a measure of how the force of gravity acts upon that mass). Mass: The amount of matter in an object (measured in kilograms). Weight: The force exerted on an object due to gravity (measured in newtons). Formula: W=mgW = mgW=mg (weight = mass × gravitational acceleration). 13. Define the law of falling bodies All objects fall at the same rate in the absence of air resistance, regardless of their mass. EXT: Define free fall and terminal velocity Free fall: The motion of an object under the influence of gravity alone.  Terminal velocity: The constant speed an object reaches when the force of gravity is balanced by air resistance. 14. Recall Newton’s 3 laws of motion 1st Law: An object remains at rest or in uniform motion unless acted upon by an unbalanced force (Law of Inertia). 2nd Law: The acceleration of an object is proportional to the net force acting on it and inversely proportional to its mass (F=ma) 3rd Law: For every action, there is an equal and opposite reaction. 15. Complete experiments or simulations to model Newton’s 3 laws of motion 16. Perform calculations using F=ma To calculate force: F=ma, where F- force, m = mass, a = acceleration 17. Recall the types of energy that exist Light energy, heat energy, mechanical energy, gravitational energy, electrical energy, sound energy, chemical energy, nuclear or atomic energy 18. Explain the difference between energy transfer (the movement of energy from one location to another) and energy transformations (the change in energy from one form to another). Energy transfer: The movement of energy from one object to another. Energy transformation: The change of energy from one form to another (e.g., potential to kinetic). 19. Use the law of conservation of energy to explain, using calculations, that total energy is maintained in energy transfers and transformations in a closed system States that energy cannot be created or destroyed, only transferred or transformed. The total energy in a closed system remains constant. GENETICS AND EVOLUTION LEARNING INTENTIONS 1. Explain that all organisms have genetic information coded in DNA molecules  DNA is a biological molecule that contains the instructions an organism needs to function, develop, and reproduce. This is present in all living things and contains each organism's genetic code. 2. Define the terms: DNA, gene, chromosome, genome - DNA: Biological molecule that codes for a protein - Gene: A section of DNA that codes for one specific protein. Eg. Melanin- brown pigment, Insulin- Hormone that reduces blood glucose levels - Chromosome: A structure found in the nucleus that is made up of DNA wrapped around proteins. Human body cells-46, Gametes- 23 - Genome- The complete set of DNA (genetic material) in an organism of one species 17. Explain the process involved in DNA replication Must occur before cell division The DNA is copied so we have 2 sets instead of 1 Requirements - Original Dna - Nucleotides ( free) From Food - Enzymes ( catalyst that speeds up reactions) - Energy 18. Recall the reasons why cells must divide Cells divide to allow multicellular organisms to grow. Cells divide to reproduce and create identical copies of themselves. Cells divide to repair damaged or dead cells in multicellular organisms. - Single celled organism (unicellular) eg. bacteria Increase population Multicellular organisms. Eg. sheep, human - Growth - Repair - Produce sperm + eggs - Increase efficiency of the delivery of important substances + removal of waste  - Cell will die if it doesn’t divide 19. Compare and contrast the process of purpose of mitosis and meiosis The purpose of mitosis is cell regeneration, growth, and asexual reproduction, The purpose of meiosis is the production of gametes for sexual reproduction. 21. Outline how genetic information is passed onto offspring via sexual or asexual reproduction Asexual reproduction: A single organism reproduces without the involvement of another organism. Genetic information is passed to offspring through mitosis, producing offspring genetically identical to the parent (a clone). Example: bacteria reproduce by binary fission. Sexual reproduction: Two parents contribute genetic material through meiosis. Gametes (sperm and egg) each carry half of the parent’s DNA. During fertilisation, the zygote formed has a complete set of chromosomes (from both parents), leading to genetic diversity. ➔ MS LEF CLASS TEXT ➔ 2 organisms of different biological sex of the same species. ➔ Male + female gametes - fertilisation sexual ➔ Variation due to : Meiosis - gamete production: crossing over ➔ Fertilisation: which sperm/ pollen gets to the egg is random 22. Outline the connection between genotype and phenotypes, using Mendelian inheritance for plants and animals Genotype - The genotype is a set of genes in DNA responsible for unique traits or characteristics Eg. XR XR = normal XR Xr = normal (carrier) Xr Xr = Colourblind ( 2 copies needed and both parents must at least carry the r) XR Y = normal Xr Y = Colourblind Phenotype- The phenotype is the physical appearance or characteristic of an organism. Connection Between Genotype and Phenotype  Mendelian Inheritance: The genotype influences the phenotype according to Mendel's laws. For example, the presence of dominant or recessive alleles affects traits: ○ In plants and animals, traits like flower colour or fur type are determined by the genotype. ○ In the case of colour blindness, individuals with their Xr Xr genotype express the colorblind phenotype, while those with at least one XR allele exhibit normal vision. 23. Use pedigrees and punnett squares to model single gene-trait relationships and make predictions about patterns of inheritance Pedigrees: A chart that shows family relationships and how traits are passed down through generations. It helps identify who has a specific trait (like color blindness) and how it might be inherited. Punnett Squares: A grid used to predict the possible genetic combinations from two parents. It shows the likelihood of offspring inheriting certain traits based on the parents’ genotypes. Example If we use a Punnett square for colour blindness (where XR is normal vision and Xr is colorblind), we can predict: ○ Parents: XR Xr , (normal vision, carrier) and XR Y (normal vision) ○ The Punnett square shows possible offspring genotypes: XR XR,XR Xr, XR Y, Xr Y. ○ This helps us see that there’s a chance for normal vision and color blindness in their children. 24. Identify causes of genetic variation (mutation, meiosis and fertilisation) Mutations: Random changes in DNA that can introduce new alleles into a population. Meiosis: During gamete formation, processes like crossing over and independent assortment shuffle alleles, creating new combinations. Fertilisation: The random union of gametes from two parents increases genetic variation in offspring. 25. Explain how the process of natural selection and isolation can lead to changes within and between species Natural selection: Organisms with favourable traits are more likely to survive and reproduce, passing on those traits to offspring. Over time, advantageous traits become more common.  Isolation: When populations of the same species are geographically or reproductively isolated, they can evolve independently, leading to the formation of new species (speciation). 26. Explain how Darwin’s finches are a good example of evolution by natural selection and isolation \ Darwin’s finches, found on the Galápagos Islands, demonstrate natural selection and adaptation. Different species of finches evolved from a common ancestor but developed distinct beak shapes based on available food sources. Geographic isolation and different environments led to the divergence of these species, illustrating speciation. 27. Investigate, using evidence, how the complexity and diversity of organisms have changed over geological timescales (fossil record) The fossil record provides evidence of how life forms have evolved over millions of years, showing gradual changes in complexity and diversity. For example, ancient fossils show simpler organisms, while more recent fossils exhibit more complex forms. 28. Describe the evidence we have for the theory of evolution - Fossil record: Shows a timeline of species evolving, with transitional forms (e.g., fish evolving into amphibians). - Dreaming stories and cave paintings by Aboriginal and Torres Strait Islander People: Oral traditions and ancient artwork that depict flora and fauna, showcasing changes in the natural world. - Homologous structures: Anatomical features in different species that are similar because they were inherited from a common ancestor (e.g., human arms, whale flippers, and bat wings). - Vestigial organs: Body parts that have lost their original function through evolution (e.g., human appendix, whale pelvis). - Embryology: Early developmental stages of different species show similarities, suggesting a common ancestor. - DNA similarities: DNA comparison (like DNA hybridization) reveals how closely related species are at the genetic level, supporting common ancestry.