Across
- 2. Oxides of nitrogen are formed from the heat and ....... found in car engine
- 5. The oxides of nitrogen comes from the use of ...... engines
- 8. Lead of lead compounds are .........., this may cause health issues
- 9. Iron comes to a rust when it comes into contact with ........ and oxygen
- 15. The composition of clean, dry air approximately are 78% ........., 21% oxygen and the rest is a mixture of noble gases and carbon dioxide
- 17. The filtered water is then .........., to kill microbes (agents used include: ozone, UV light or chlorine)
- 18. A method where a less reactive metal can be coated with a more reactive metal to prevent it from rusting (e.g. iron and steel can be coated by zinc), this works as the more reactive metal is oxidised by oxygen in the air (i.e. rusts), protecting the less reactive metal underneath
- 22. ......... converters are used to remove oxides of nitrogen, carbon monoxide + nitrogen monoxide ---> nitrogen + carbon dioxide, nitrogen and carbon dioxide are relatively harmless gases compared to carbon and nitrogen monoxides
- 23. The colour change when white anhydrous copper(II) sulphate is in presence of water
- 24. Carbon monoxide comes from the ......... combustion of carbon-containing substances
- 25. The colour change when blue anhydrous cobalt(II) chloride is in presence of water
- 26. Humans need drinking water with low levels of dissolved ....... and microbes
- 30. Water is ........ for life
- 31. Lead compounds come from the use of leaded ...........
Down
- 1. Oxygen has a boiling point ......... than that of nitrogen
- 2. ........, coating with oil/ grease, coating with plastic/ other metal, are some methods to prevent rusting
- 3. Fractional distillation of liquid air ....... oxygen and nitrogen
- 4. An .......... source of fresh water is selected (rain provides water with low levels of dissolved substances and this collects in the ground/ rivers/ lakes)
- 6. Petrol is used on a ......... scale, so these problems affect the whole world, like the damage of property to health issues, meaning this needs to be addressed globally
- 7. The water from rain is passed through ....... beds to remove different sized insoluble solids (filtration)
- 10. Water of correct quality is essential for life. It must be free of ........... salts and harmful microbes
- 11. The common ........ in the air are carbon monoxide, sulphur dioxide, oxides of nitrogen, and lead compounds
- 12. Water covers about 2/3 of our plant, but the majority cannot be drunk .........
- 13. Some uses of water in ........... include using water as a solvent and using water as a coolant
- 14. We also need water for ......... crops
- 16. Carbon monoxide, a poisonous gas causes health problems like ......... difficulties, because it reduces the amount of oxygen that RBC can carry around the body. As well as poisoning which leads to death when too much carbon monoxide
- 19. Sulphur dioxide form ........ rain which kills plants and aquatic life, erodes stonework, and corrodes metals
- 20. You may keep oxygen away from iron by storing it in a ......... container
- 21. Sulphur dioxides comes from the ......... of fossil fuels which contain sulphur compounds (leading to 'acid rain')
- 27. Some uses of water in ........ include drinking water, heating, and plumbing
- 28. In the separation of oxygen and nitrogen, air is liquefied (around -200 degrees Celsius), fractional distillation column temperature is increased until nitrogen boils and rises to the top as a gas (around -196 degrees Celsius), the nitrogen is then collected and ..........., the temperature is increased until oxygen boils and rises to the top as a gas ( around -183 degrees Celsius) and oxygen is collected
- 29. Oxides of nitrogen ...... with other pollutants, in sunlight, forming a photochemical smog, which cause breathing difficulties, as well as form acid rain which kills plants and aquatic life, erodes stonework, and corrodes metals