Science

Ecosystems are always changing, yet healthy ones stay in balance for centuries. In this unit you will find out how. You will see Earth as four interacting spheres, follow energy as it flows from the Sun through food webs and leaves as heat, and trace matter as it cycles through the carbon, nitrogen and phosphorus cycles. You will compare photosynthesis and cellular respiration and explain how their partnership keeps the air in balance. You will investigate how biodiversity, air and water quality, soil health and succession keep ecosystems sustainable, and how human activities push them out of dynamic equilibrium.

In the second half you will explain how human activities are causing climate change, use real indicators to describe its impacts on local and global ecosystems, and assess its impacts on communities in Canada, including First Nations, Métis and Inuit communities. You will finish with solutions: sustainable practices of First Nations, Métis, Inuit and other communities, initiatives from your town to the Paris Agreement, and agricultural innovations that cycle matter and use energy wisely.

Remember from earlier grades: Grade 7 Interactions in the Environment (food chains, cycles, succession, Two-Eyed Seeing) and Heat in the Environment (the greenhouse effect), and Grade 8 Cells and Water Systems. Every lesson has a hands-on activity, worked examples, practice at three levels and a quiz; some include short Python programs. Safety: a grown-up should help with anything involving knives, lamps, fertilizer or digging, and never taste or drink samples.

Curriculum expectations covered: B1.1, B1.2, B1.3, B2.1, B2.2, B2.3, B2.4, B2.5, B2.6, B2.7 (Ontario Science, Grade 9, SNC1W, 2022, Strand B: Biology: Sustainable Ecosystems and Climate Change), with STEM skills, careers and connections from Strand A (A1.1 to A1.5, A2.1 to A2.5).

What is everything made of, and why do substances behave the way they do? In this unit you will go inside the atom. You will describe matter by its physical and chemical properties, including the products under your sink and the hazard symbols on them. You will follow the experimental evidence that took scientists from Dalton's solid spheres to the Bohr-Rutherford model, and learn to count protons, neutrons and electrons and draw atoms. You will discover why the periodic table is arranged the way it is, investigate metals, nonmetals, metalloids and chemical families, and see how atoms form ionic and molecular compounds whose formulas match their structures.

Then you will use chemistry to understand the world: the reactions and properties that keep ecosystems in balance, the life cycle of the products you buy, and emerging chemical technologies in fields such as the skilled trades. Strand A skills (investigating safely, including WHMIS, designing fair tests, coding, and connecting science to careers and society) are woven through the lessons.

This unit builds on Grade 7 (pure substances, elements and compounds) and leads to the Grade 10 chemistry unit on chemical reactions.

In this unit you will study electricity the way physicists and electricians do. You will start inside the atom, using protons and electrons to explain static electricity and the three ways of charging an object: friction, contact and induction. You will investigate which materials hold charge and which transfer it (insulators and conductors).

Then you will move to current electricity. You will define electric current, potential difference and resistance, with their symbols and SI units, read and draw DC circuit diagrams with standard symbols, and use ammeters and voltmeters correctly. You will investigate how current depends on potential difference and resistance and build a mathematical model, Ohm's law (V = I × R), then use it to solve real problems and to explain electrical safety. You will build and compare series and parallel circuits.

Finally, you will explain the difference between electricity and electrical energy, calculate power, energy in kWh and efficiency, and assess how Ontario produces electrical energy, how those choices affect different communities, including First Nations communities, and how emerging technologies and conservation can make our use of electrical energy more sustainable. You will finish by writing your own plan of action.

Remember from Grade 6: static and current electricity, conductors and insulators, simple circuit diagrams, and series and parallel circuits. Grade 9 adds atomic explanations, measurements, units and calculations. If you take Grade 11 Physics, you will study electricity and magnetism in even more depth.

Safety first: experiments in this unit use only small AA batteries or coin cells, or free online simulations. Never experiment with wall outlets, never connect a wire straight across a battery, and keep coin cells and balloons away from young children.

Curriculum expectations covered: D1.1, D1.2, D1.3, D1.4, D2.1, D2.2, D2.3, D2.4, D2.5, D2.6, D2.7, D2.8 (Ontario Science, Grade 9, De-streamed, SNC1W, 2022, Strand D: Physics), with STEM skills and connections from Strand A (A1.1, A1.2, A1.4, A1.5, A2.2, A2.3, A2.4).

How does a star shine for billions of years? How far away is the nearest star, and how can anyone know? What happened at the very beginning of the universe, and how do satellites help us understand our own changing planet? In this unit of Grade 9 Science (SNC1W) you will explore space the way scientists do: with evidence, measurement, models and careful thinking about impacts.

You will:

• look inside the Sun, learn how nuclear fusion powers it, and trace how its energy drives winds, the water cycle, auroras and renewable energy;
• compare the members of the solar system, stars and galaxies using real data;
• quantify huge distances with scientific notation, astronomical units and light-years, and build scale models;
• summarize the evidence for how the solar system formed and for the Big Bang, and learn about First Nations, Métis and Inuit and other ways of knowing the sky;
• investigate the causes of seasons, Moon phases, eclipses, tides and meteor showers;
• evaluate how satellites help us understand climate change and natural disasters, how space technology is used on Earth, and the social, environmental and economic impacts of space exploration.

Each lesson has hands-on activities you can do at home (some need a grown-up), worked examples, practice questions with answers, and a quiz. The unit builds on Grade 6 Space and connects to the Biology (climate change) and Electricity strands of this course.