science test

Evidence of Chemical Changes

Colour change, gas/bubbles, temperature change, precipitate formation, light or sound production

Lewis Diagrams

Show valence electrons as dots around element symbols

Forming Ions

Metals lose electrons → positive ions; nonmetals gain electrons → negative ions; show electron transfer with arrows

Ionic vs Covalent Compounds

Ionic: metal + nonmetal, electrons transferred | Covalent: nonmetal + nonmetal, electrons shared

Ionic Bonding

Electrons transfer from metal to nonmetal; oppositely charged ions attract

Naming Simple Ionic Compounds

Metal name + nonmetal with "-ide" ending (e.g., NaCl = sodium chloride)

Multivalent Ions

Metals with more than one possible charge; use Roman numerals in name (e.g., iron(III) chloride)

Polyatomic Compounds

Contain a polyatomic ion (e.g., Ca(NO₃)₂ = calcium nitrate)

Covalent Bonding

Electrons are shared between nonmetals

Naming Covalent Compounds

Use prefixes (mono-, di-, tri-, etc.) to indicate number of atoms (e.g., CO₂ = carbon dioxide)

Writing Chemical Equations

Reactants → Products; include state symbols (s, l, g, aq)

Predicting Products

Use reaction type to predict products (e.g., synthesis forms one product)

Law of Conservation of Mass

Mass is neither created nor destroyed; mass of reactants = mass of products

Balancing Equations

Use coefficients to ensure equal numbers of each type of atom on both sides

Endothermic vs Exothermic

Endothermic: absorbs heat (cold) | Exothermic: releases heat (hot)

Types of Reactions

Synthesis, decomposition, single displacement, double displacement, combustion

Acids vs Bases

Acids: pH < 7, sour, turn litmus red | Bases: pH > 7, bitter, slippery, turn litmus blue

pH Concept & Indicators

pH 0–14 scale; indicators include litmus, phenolphthalein, universal indicator

Cell Organelles

Nucleus, mitochondria, ribosomes, ER, Golgi, lysosomes, membrane – each with specific functions

Plant vs Animal Cells

Plant: cell wall, chloroplasts, large vacuole | Animal: no wall/chloroplasts, small vacuoles

Importance of Cell Division

Needed for growth, repair, replacement, reproduction

Cell Cycle

Interphase (G1, S, G2) → Mitosis → Cytokinesis

Stages of Mitosis

Prophase, Metaphase, Anaphase, Telophase; describe each and identify in images

Cancer & Tumours

Cancer = uncontrolled cell division; tumour = mass of abnormal cells

Specialized Cells

Examples: red blood cell, neuron, muscle cell, root hair cell – each has unique function

Digestive System

Breaks down food; organs: mouth → esophagus → stomach → intestines; steps: ingestion to elimination

Circulatory System

Transports substances; includes heart, blood vessels; carries oxygen, nutrients; arteries vs veins

Respiratory System

Gas exchange system; includes lungs, trachea, bronchi; breathing vs cellular respiration

Musculoskeletal System

Supports body & enables movement; bones, ligaments, tendons, cartilage; voluntary vs involuntary

Nervous System

Controls body; CNS (brain + spine), PNS (nerves); sensory, motor, interneurons; neurons transmit signals

Sources of Light

Bioluminescence, chemiluminescence, incandescence, fluorescence, phosphorescence, triboluminescence

Law of Reflection

Angle of incidence = angle of reflection; parts: incident ray, reflected ray, normal

Reflection vs Refraction

Reflection: bouncing light | Refraction: bending of light when changing medium

Total Internal Reflection (TIR)

Occurs when light reflects back entirely at boundary; must enter slower medium at large angle

Refraction Direction

Toward normal = entering slower/denser medium | Away from normal = entering faster/less dense medium

Index of Refraction (n = c/v)

n = index of refraction | c = speed of light in vacuum | v = speed of light in medium

Thin Lens Equation (1/do + 1/di = 1/f)

Use to calculate object distance (do), image distance (di), or focal length (f)

Magnification Equation (hi/ho = -di/do)

Find image height, object height, or distances; negative sign shows image inversion

Ray Diagrams

Use rules to find image location and characteristics (SALT)

SALT for Images

Size, Attitude (upright/inverted), Location, Type (real/virtual)

Mirror & Lens Types

Plane: virtual, upright | Concave: real or virtual | Convex: always virtual | Converging lens: real/virtual

Image Types by Object Location

Concave mirror/converging lens: object beyond 2F = real | object inside F = virtual | Convex mirror = always virtual

Greenhouse Effect

Gases trap heat in the atmosphere; e.g. CO₂, CH₄, H₂O vapor, N₂O

Evidence for Climate Change

Melting ice, rising sea levels, extreme weather, global temps rising, ecosystem shifts