Science Exam Review PDF

Science Exam Review: Chemistry: Physical vs Chemical Change: Evidence of Chemical Change: -​ Change in colour -​ Change in odour -​ Precipitate -​ Gas release (bubbles formed not from heating) -​ Change in temperature or light Differences: -​ Chemical change is not reversible...

Science Exam Review: Chemistry: Physical vs Chemical Change: Evidence of Chemical Change: -​ Change in colour -​ Change in odour -​ Precipitate -​ Gas release (bubbles formed not from heating) -​ Change in temperature or light Differences: -​ Chemical change is not reversible (frying an egg), physical change can be -​ Physical change involves change of shape, form, or appearance Atoms vs Ions: -​ Protons are positive, electrons are negative, neutrons are neutral -​ Losing or gaining electrons creates an imbalance in charges within the atom -​ When an atom become imbalanced, it becomes an ion (the number of protons is not equal to the number of electrons) Cations vs Anions: -​ Metals tend to lose electrons to form a full valence shell and become a positively charged cation -​ Nonmetals tend to gain electrons to form a full valence shell and become negatively charged anions Naming ions: -​ Metals add ion to the end of the name (sodium = sodium ion) -​ Nonmetals add “ide” to the prefix (oxygen = oxide) Patterns on the periodic table: -​ Periods go across the periodic table, groups are the vertical columns -​ The period number represents the number of shells in a bohr-rutherford diagram -​ The group number represents the number of valence electrons in its outermost shell Ionic Compounds: -​ Ionic compounds are made up of positive cations and negative anions -​ These compounds are the result of a transfer of electrons from the metal to the nonmetal -​ The attraction that holds the oppositely charged ions is called an ionic bond Properties: -​ Solid at room temp (forms a crystal lattice structure) -​ Hard, brittle, high melting point -​ Contains electrolytes Naming: -​ The metal ion goes first in the name. Nothing changes (sodium stays as sodium) -​ The nonmetal is second. The name of the nonmetal ion changes to “ide” (chlorine = chloride)  -​ Ex. the name of sodium and chlorine is sodium chloride Chemical Formulas for Ionic Compounds: -​ Write the symbols of each chemical involved (Write the metals on the left and nonmetals on the right) -​ Write the ionic charge above each symbol and criss cross the charges -​ Reduce if possible Multivalent Ions: -​ Some elements (usually transition metals) form more than one stable cation and are known as multivalent metals -​ They are named like cations, but the ionic charge is written in Roman numerals in rounded brackets -​ Ex. Lead (IV) Polyatomic Ions: -​ Groups of atoms that tend to stay together and act as a single charged particle -​ The ionic charge is shared over the whole ion, rather than just one atom Naming: -​ Same as regular ionic bonds, cation is named first then the anion Molecular Compounds/Covalent Bonding: -​ When two nonmetals combine to form a molecule, they are held together by a covalent bond (they share electrons rather than transferring them) Diatomic Molecules: -​ A molecular compound formed by two identical atoms -​ HOFBrINCl -​ Ex. Oxygen (O2) Properties: -​ Can be solid liquid or gas at room temperature -​ Low melting and boiling points -​ Non-conductive Naming: 1.​ Write the name of the elements found in the compound 2.​ Use greek prefixes to indicate the number of atoms present (mono is not used for the first element) 3.​ Replace the ending of the second nonmetal to “ide” Greek Prefixes 1 Mono 6 Hexa 2 Di 7 Hepta 3 Tri 8 Octa 4 Tetra 9 Nona 5 Penta 10 Deca Chemical Reactions: -​ An interaction between substances that leads to the creation of a new substance with new properties -​ Reactions can be described in a word equation or a chemical equation Reactants: substances that are used up in the reaction (starting material) Products: substances that are created after the reaction occurs -​ Reactions can release energy (exothermic) or absorb energy (endothermic) Law of conservation of mass: -​ Mass of reactants = mass of products -​ # of atoms in reactants = # of atoms in products -​ This stems from the idea that matter cannot be created or destroyed -​ Can be represented by a balanced chemical equation Balancing equations: -​ The ratio of atoms never changes (the subscripts are always the same) -​ In chemical equations, the only number that can be changed is the number of molecules of each element -​ Only the coefficients can be changed, not the subscripts Note: when balancing with polyatomic ions, treat them as one unit, rather than individual atoms, so long as the appear the same on the product side Types of Reactions: Synthesis: -​ Two or more reactants combine to form a new and larger product -​ A + B = AB -​ Ex. Zn + S → ZnS Decomposition: -​ One compound breaks down into two or more smaller compounds -​ AB = A + B -​ Ex. MgCl → Mg + Cl Single Displacement: -​ One element takes the place of another element in a compound -​ AB + C = AC + B -​ Ex. Mg + HCl → MgCl + H (note: this is unbalanced) Double Displacement: -​ The metal ions of two different compounds change places -​ AB + CD = AD + CB -​ Ex. NaOH + HCl → HOH + NaCl Combustion Reaction:  -​ Reaction involving the burning of hydrocarbon (compounds containing carbon and hydrogen) with oxygen -​ The products are always carbon dioxide and water -​ CH + O2 = CO2 + H2O Complete Combustion Incomplete Combustion -​ Occurs when there is an excess of -​ Occurs when oxygen supply is limited oxygen -​ Produces CO2, CO, C, H2O, and -​ Products are always CO2, H2O, and energy energy -​ Produces flames that are sooty, -​ Most efficient way to burn energy yellow, and cooler flames -​ Produces clean and hot flames (blue in colour) Acids vs Bases: -​ Acids tend to form hydrogen ions -​ Bases tend to form hydroxide ions Properties: Acids: Bases: -​ Sour taste -​ Bitter taste -​ Soluble in water -​ Soluble in water -​ Electrolytes present -​ Electrolytes present -​ Reacts with most metals -​ Feels slippery -​ Reacts with carbonates -​ Blue litmus paper stays blue -​ Blue litmus paper turns red -​ Red litmus paper turns blue -​ Red litmus paper stays red -​ Phenolphthalein turns pink -​ Phenolphthalein remains colourless Naming: Acids: -​ There are two types: binary (two elements) and oxy-acid (has oxygen in the formula) -​ Binary: Hydrogen becomes “hydro,” nonmetal gets replaced with “ic” -​ Ex. HCl = hydrochloric acid -​ Oxy-acid: Drop hydrogen, “-ate” ending becomes “ic,” add acid at the end -​ Ex. HClO4 = Chloric acid Bases: -​ Bases always have OH as the anion -​ Name it like any other ionic compound with a hydroxide ion -​ Ex. NaOH = Sodium hydroxide The pH Scale: -​ Used to measure the strength of acids and bases -​ pH: the power of a hydrogen ion -​ The scale ranges from 0-14 and indicates the acidity of the solution  -​ The pH scale is logarithmic, meaning that 1 pH unit increases or decreases tenfold in the amount of hydrogen ions that are in a substance Biology: Organelles: Cell Membrane: -​ Separates the inside of the cell from the outside environment -​ Controls the flow of materials in and out of the cell (semi permeable) -​ Provides support and flexibility for the cell The nucleus: -​ Surrounded by a thin membrane called the nuclear membrane -​ The control center of the cell. Controls all functions and all activities -​ Stores DNA Nucleolus: -​ Makes ribosomes Chromosomes: -​ Made up of chromatids, which coil to form chromosomes -​ Contains genetic information for the cell Mitochondria: -​ The powerhouse of the cell -​ Provides energy for the cell through cellular respiration -​ The more energy a cell needs, the more mitochondria it has Endoplasmic Reticulum: -​ A series of tunnels and canals that runs from the cell membrane to the nuclear membrane -​ Helps transport materials throughout the cell -​ Smooth: Involved in the production of fats -​ Rough: Contains ribosomes, involved in the production of proteins Ribosomes: -​ Small organelles that make protein -​ Can be connected to the rough endoplasmic reticulum or free floating Golgi Apparatus: -​ Packages and sorts materials (water, waste, proteins) that are leaving the cell -​ Packs them into sac-like structures called vesicles that will travel outside the cell Vacuole: -​ Used for support and storage within the cell -​ Holds waste, water, food, protein, etc  -​ Animals have many small vacuoles, plant cells have one large vacuole Lysosome (Animal Only): -​ Contains enzymes that break down waste -​ Breaks down invading bacteria and damaged organelles Centrioles (Animal Only): -​ Involved in cell division Chloroplast (Plant Only): -​ Contains chlorophyll (makes plants green) -​ The site of photosynthesis, which allows plants to make their own food Cell Wall (Plant Only): -​ Additional covering for the cell after the cell membrane -​ Provides rigid and firm support and protection for the cell Prokaryote vs Eukaryote: -​ Prokaryote: a cell that does not contain a nucleus or other membrane-bound organelles -​ Ex. Bacteria, such as e.coli -​ Eukaryote: a cell that contains a nucleus and other organelles, each surrounded by a thin membrane -​ Ex. Animal and plant cells Stem Cells: -​ Cells develop in different ways to perform specific functions through a process called cellular differentiation -​ Every cell in your body initially came from a small group of stem cells, which are unspecialized cells -​ This means that stem cells are capable of becoming any cell within the human body, which could have many medical implications, such as regeneration Embryonic Stem Cells: -​ Found in the embryo -​ Are able to differentiate into other cell types Tissue (adult) Stem Cells: -​ As organisms mature, stem cells become specialized. Therefore, there are very few examples of stem cells within the human body -​ Most tissue stem cells are used in replacement of damaged tissue -​ Locations include skin, blood, and neutral tissues Blood Cell Banking: -​ Stem cells can be harvested from the umbilical cord, however there are only a few of them -​ The blood containing these cells can be “banked” for future use -​ Can also be found in bone marrow Cell Cycle:  -​ Made up of two stages: Interphase (growth phase) and division stage (mitosis and cytokinesis) Interphase: -​ Growth phase (G1): cell is carrying out metabolic processes and activities -​ Synthesis: cell makes an entire identical copy of its DNA -​ Growth phase (G2): Cell moves into its second growth phase where it approaches maximum size and makes the necessary structures for cell division -​ Interphase is approximately 90% of the cells life Prophase: -​ Chromosome coils thicken (2 sister chromatids are held together by a centromere to form one chromosome) -​ Nuclear membrane disappears -​ Centrioles start to move to opposite poles -​ Spindle fibres begin to form Metaphase: -​ Centrioles have reached opposite poles -​ Spindle fibres begin to attach to the centromere on each chromosome and line them up in the middle of the cell Anaphase: -​ Chromosomes split -​ Sister chromatids go to opposite poles Telophase: -​ Nuclear membrane forms around the new nucleus of each set -​ Chromosomes stretch out and become thin Cytokinesis: -​ Cytoplasm and other organelles are divided equally into each new cell -​ Cell membrane forms around each new cell Cytokinesis in animals vs plants: -​ Animal: the cell membrane pinches in the middle and forms a cleavage furrow -​ Plant: a cell plate forms between the new cells which eventually grows into a part of the cell wall Cancer Cells: -​ A broad group of diseases that result in uncontrolled cell division -​ This uncontrolled growth and division results in a large mass of cells forming, called a tumour, which serves no purpose -​ Cancer cells can take up oxygen and nutrients, which hurts normal cells and can cause them to stop reproducing -​ Can also lead to crowding within the body Benign:  -​ A tumour that has no function, but doesn’t cause harm to any surrounding tissue other than crowding it. -​ Benign tumours are not cancerous Malignant: -​ A tumour that interferes with the function of the tissues it surrounds -​ Malignant are cancerous cells -​ May interfere with the production of hormones or enzymes, and may destroy surrounding tissue Metastasis: -​ The process of cancer cells breaking away from the tumour and establishing another tumour somewhere else in the body Benign Malignant -​ Encapsulated -​ Not encapsulated -​ Non-invasive -​ Invasive -​ Limited growth -​ Uncontrolled growth -​ Does not metastasize -​ Can metastasize -​ Rarely lethal -​ Often lethal ABCD’s: -​ Benign: Symmetric shape, even border, uniform colour, less than 6mm -​ Malignant: Asymmetric shape, uneven border, uneven colour, more than 6mm Digestive System: Function: -​ Break down food -​ Absorption of nutrients -​ Elimination of waste 4 Stages: 1.​ Ingestion: the taking in of food/nutrients 2.​ Digestion: chemically or mechanically breaking down food into smaller pieces 3.​ Absorption: taking nutrients into the bloodstream 4.​ Elimination: the removal of waste products Teeth: -​ Used for mechanical breakdown of food -​ Ingestion and digestion Salivary Glands: -​ Chemical digestion -​ Mixture of water mucus and amylase, which is an enzyme that breaks down carbohydrates Tongue and Pharynx: -​ Mechanical digestion -​ The tongue rolls food to form a bolus, which then goes down the pharynx -​ The epiglottis is the trapdoor that makes sure that your food travels down the digestive tract and not the respiratory tract Esophagus: -​ A muscular tube that connects the mouth to the stomach -​ Peristalsis: the rhythmic contractions of muscles in the esophagus that pushes food down towards the stomach Sphincters: -​ Muscles that contract to control the amount of food going in and out of the stomach and anus -​ 3 types: cardiac sphincter (at the top of the stomach), pyloric sphincter (at the bottom of the stomach), and the anal sphincter (at the anus) Stomach: -​ Mechanical and chemical digestion -​ Secretes gastric juice (HCl and enzymes that break down protein) and mucus that protects the stomach lining Small intestine: -​ Digestion and absorption -​ Contains enzymes that further break down carbohydrates, proteins, and fats -​ Nutrients get absorbed into the bloodstream -​ Length of 7m Large intestine: -​ Absorption of water and elimination -​ 1.5m long Liver (accessory organ): -​ Produces bile which breaks down fats (emulsification) -​ Detoxifies harmful substances and breaks them down into non-harmful substances Gallbladder: -​ Stores bile -​ Attached to small intestine Pancreas: -​ Produces insulin, which regulates the amount of glucose in blood -​ Attached to the small intestine -​ Pancreatic enzymes: breaks down protein and carbohydrates in the small intestine Circulatory System: Function: -​ Transport substances (nutrients, hormones, waste products, oxygen) around the body -​ Regulation of body temperature 3 main parts: -​ Blood: transports various materials -​ Heart: a pump that pushes blood through vessels -​ Blood vessels: network of tubes that blood travels through Blood: -​ Constantly being made in bone marrow  -​Transports oxygen, hormones, and heat -​Removes waste such as carbon dioxide (travels to the lungs) and other waste products (travels to the liver) Components: -​ Red blood cells (45%), carries oxygen -​ White blood cells (1%), fights and destroys bacteria and viruses -​ Platelets (>1%), helps blood clot to seal wounds and stop bleeding -​ Plasma (55%), carries blood cells, hormones, nutrients and waste Heart: -​ Contains pacemaker cells that send electrical impulses telling the chambers of the heart to contract -​ Contains valves to keep blood moving in the right direction Structure: -​ Contains 4 chambers, 2 upper small chambers (left and right atrium), and 2 lower larger chambers (left and right ventricles) -​ Chambers are separated by valves that allow the blood to pass within the chambers of the heart Blood Vessels: -​ Network of tubes that carry blood throughout the body Arteries: -​ Have thick, muscular walls -​ Carry blood away from the heart -​ Experience more blood pressure Veins: -​ Thinner walls -​ Carries blood towards the heart -​ Has valves that makes sure blood travels in the right direction Capillaries: -​ Tiny blood vessels (one cell thick) with very thin walls -​ Blood cells travel through in a single file line -​ Capillaries link arteries and veins together Note: right side of the heart carries deoxygenated blood to the lungs, left side of the heart carries oxygenated blood to tissues around the body Respiratory System: Function: -​ Providing oxygen for the body -​ Removal of carbon dioxide produced by the body as it uses energy Note: the respiratory system works closely with the circulatory system to provide oxygen and remove carbon dioxide from the body Passage of Air:  -​ Mouth and nose, pharynx, larynx, trachea, bronchi, lungs Trachea: -​ Supported by rings of cartilage that keep the trachea open and allow air to flow freely -​ Lined with layers of cilia and mucus that trap dirt and bacteria Alveoli: -​ Sacs attached to the end of bronchi -​ Have thin walls and are surrounded by capillaries -​ The site of gas exchange Breathing: -​ Inhalation: drawing air into the lungs -​ Exhalation: pushing air out of the lungs -​ Breathing uses muscles that move the diaphragm and rib cage -​ When we inhale, our chest expands and our diaphragm contracts -​ When we exhale, our chest contracts and our diaphragm relaxes Physics: Electromagnetic Waves: -​ A form of radiation that can travel through a vacuum -​ The electromagnetic spectrum is a chart that shows different types of radiations ranked in terms of strength -​ Strength of electromagnetic wave is determined by the length of the wavelength (the longer the wave, the weaker it is) Order (lowest to highest): 1.​ Radio waves 2.​ Microwaves 3.​ Infrared rays 4.​ Visible light (ROYGBIV) 5.​ Ultraviolet light 6.​ X-Rays 7.​ Gamma rays Laws of Reflection: 1.​ The angle of incidence always equals the angle of reflection 2.​ The angle of incidence, angle of reflection, and the normal all lie on the same plane Specular vs Diffuse: -​ Specular reflection occurs when light is reflecting off a smooth and shiny surface, resulting in reflected rays all being parallel to each other -​ Diffuse reflection occurs when light is reflected off an irregular surface that may be dull. This results in reflected rays that go in all different directions Salt: -​ Size (smaller, same, larger than original object) -​ Attitude (upright, inverted, laterally inverted) -​ Location (infront or behind mirror, where the object is for lenses)  -​ Type (real or virtual image) Images in plane mirrors: -​ All plane mirrors will produce virtual images because our eyes track light back as a straight line -​ So, when light reflects back to our eyes off the mirror, we trace it back to be behind the mirror, creating a virtual image Salt for plane mirror: -​ Size: Same -​ Attitude: Laterally inverted -​ Location: Behind mirror -​ Type: Virtual Concave Mirrors (Converging): -​ A mirror in which the reflective surface is caved in at the center -​ Ex. inside a spoon, headlights, makeup mirror -​ Note: if the object is located at the focal point no image will be produced Convex Mirrors (Diverging): -​ A mirror in which the reflective surface faces out -​ Reflected rays will never meet in a convex mirror, therefore the image produced will always be virtual -​ Ex. parking lot mirrors, side-view mirrors, security mirrors Refraction: -​ The bending of light as it passes through one medium to another -​ Occurs because the speed of light in different media changes (it goes faster in some and slower in others) Laws of Refraction: 1.​ The incident ray, the reflected ray, and the normal all lie on the same plane 2.​ If a light ray travels from a media that is faster into a slower medium, it will bend towards the normal. If a light ray travels from a medium that is slower into one that is faster, it will bend away from the normal Lenses: -​ A curved transparent object that refracts light in a predictable way that can be made useful (camera lenses) Converging lens: -​ A lens that is thicker in the middle and thinner at the edges -​ When parallel rays pass through a converging lens, they all converge at the principal focus Diverging Lens: -​ Thinner at the edges and thicker at the middle -​ When parallel rays pass through a diverging lens they spread apart Focusing Problems: Hyperopia:  -​ Can see distant objects clearly but not nearby objects (farsightedness) -​ Light rays from nearby objects diverge more strongly and the eyes lens isn’t thick enough to diverge them properly, causing the image to form behind the retina -​ To correct this, use a converging lens (positive meniscus) Myopia: -​ Nearby objects can be seen clearly but not distant objects (nearsightedness) -​ Parallel rays from the distant objects are refracted to strongly through the lens, causing the image to be formed in front of the retina instead of on it -​ Occurs because the lens cannot be made thin enough -​ To correct this, use a diverging lens (negative meniscus) Presbyopia: -​ A form of farsightedness where the eye loses its elasticity -​ Usually results in difficulty reading small print as the individual gets older -​ Can also be fixed with a converging lens