Across
- 3. change of state from a liquid to a solid.
- 4. slow chemical change that occurs when oxygen in the air reacts with a metal
- 5. element that has both metallic and non-metallic properties
- 7. ratio of the useful energy outpuoman area of higher concentration to one of lower concentration
- 10. group 17 elements in the periodic table;the most reactive non-metals
- 12. chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
- 15. organic molecules made up of atoms of carbon, hydrogen, and oxygen (e.g., pasta, rice,potatoes, fruits, bread); can form simple molecules,such as sugar, or large, complex molecules, such asstarch, cellulose, and glycogen p. 199carbon monoxide (CO(g))colourless, odourless gas;produced by incomplete combustion of chemicalscontaining carbon (e.g. hydrocarbons); majorsource: motor vehicles p. 227catalyst substance that helps a chemical reactionto proceed more quickly p. 166cellular respiration chemical reaction that takesplace in cells; food (sugar) reacts with oxygen toproduce energy, water, and carbon dioxide p. 160charge separation concentration of like charges inspecific areas of a neutral object, caused by theapproach of a charged object; for example, anegatively charged object brought close to a wall
- 16. ability of a substance to conduct electricity or heat
- 20. mass mass of one atom of an elementcalculated from the total number of protons,neutrons, and electrons of that atom; measured inatomic mass units (amu) atomic mass unit measure of atomic mass; 1 amuis equal to 1/12 ththe mass of a carbon 12 atomp atomic number number of protons in the nucleusof one atom of an element
- 22. dull, brittle element that does not conduct electricity
- 24. invisible negatively charged particle that orbits the nucleus of an atom
Down
- 1. process in which molecules move fr
- 2. electricity) description of an object that has equal amounts of positive and negative charges
- 4. reactions reaction that takes place when two or more substances react to form new substances
- 6. compound that dissolves in water to form a solution with a pH higher than 7
- 8. mixture in which tiny particles ofone substance are held within another andparticles cannot be separated out from the othersubstance
- 9. that has become electrically chargedbecause it has lost or gained electrons; a positiveion is an atom that has lost one or more electrons;a negative ion is an atom that has gained one ormore electrons
- 11. compound that dissolves in water to form a solution with a pH lower than 7
- 13. to the total energy input in a device or system; usually given as a percent
- 14. change of state from a solid to a liquid.
- 17. a material that electric charge can move through easily
- 18. metals group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals alkaline-earth metals group 2 elements in the periodic table; their reactivity is not as strong as that of the alkali metals
- 19. the smallest part of an element that is representative of that element; a neutral particle made up of a nucleus containing protons and neutrons, and in which the number of electrons equals the number of protons
- 21. chemical combination of two or more elements in a specific ratio
- 23. shiny, malleable, ductile element that conducts electricity
- 24. metalsmetals that have a density of 5 orhigher (e.g., copper, zinc, lead, mercury, cadmium,nickel); heavy metals are one type of substancemonitored to determine water quality