Across
- 3. Prehistoric – used stone and ________ tools to plants crops, hunt animals and chop wood.
- 4. Air is mostly __________ and oxygen.
- 10. Carbon ____________ (CO) is extremely poisonous. When Carbon monoxide molecules enter the lungs, the body’s red blood cells treat CO like oxygen.
- 12. Using a chemical reaction called nitrogen _____________, a few plants are able to change nitrogen from the air into compounds called nitrates.
- 13. Canada is the world’s top exporter of minerals such as iron, nickel, copper, _____________ and zinc.
- 15. The first step in the Metallurgy Process is crushing the rocks and separating the mineral from waste materials such as ________.
- 16. ______________ can form compounds with nitrate or phosphate called potassium nitrate (KNO_3) or potassium phosphate (K_3PO_4).
- 18. _______________ is the technology of separating a metal from its ore (rock).
- 19. Ozone at ground level is harmful to living things. It can damage plants and cause ____________ problems to humans.
- 20. Plants that grow in soil have been carefully enriched by the addition of chemical substances. These substances added to the soil to help plants to grow are called ____________.
- 23. Ozone (O_3) is formed in the upper layers of the ______________.
- 27. __________ use Carbon dioxide to make Oxygen.
Down
- 1. Carbon _________ (CO_2) is necessary for life on Earth. Carbon dioxide is released in the air by humans and by emissions from cars, factories etc.
- 2. Solder is an alloy of _________ and tin. Solder is melted to join metal pieces such as electronic components, pipes or wires.
- 5. Oxygen (O_2) makes up about 21% of the air you breathe and is called oxygen gas. All ___________ need oxygen to survive.
- 6. ______________ are naturally occurring compounds that contain a metal combined with oxygen, sulfur or other elements.
- 7. Producing the metal from the mineral in the metallurgy process involves ___________ changes.
- 8. Centuries later – mixing copper and tin to make a metal alloy called ___________.
- 9. _____________ is a chemical process in which plants combine carbon dioxide from the air/water and energy from the Sun to produce sugars and oxygen gas.
- 11. Nitrogen gas mixed with ________ produces Nitrogen Dioxide (NO_2) which is a toxic gas and it causes a yellow haze in the air.
- 14. ____________ production is one of the most important natural resource industries in Canada.
- 17. The Ozone layer is very important to life on Earth because it ________ most of the Ultraviolet rays (UV rays) from the Sun.
- 21. ____________ come from minerals in the soil and some from decomposing plant and animal matter.
- 22. Plants absorb phosphorus in the form of compounds called ______________.
- 24. Minerals are mixed with many compounds in rocks called __________. Ex: calcium – limestone (CaCO_3).
- 25. ____________ is harmless and is used for filling electric light bulbs and fluorescent tubes.
- 26. ____________ are metals melted and mixed with other metals.