Our understanding of matter has developed over time.

1. Our understanding of matter has developed over time. Lesson Objective: Students will be able to distinguish between observation and theory, and will demonstrate an understanding of the origins of the periodic table.

2. Alberta Science Curriculum • Foundation 1 • Science, Technology and Society (STS)—Students will develop an understanding of the nature of science and technology, the relationships between science and technology, and the social and environmental contexts of science and technology.

3. Foundation 2 • Knowledge—Students will construct knowledge and understandings of concepts in life science, physical science and Earth and space science, and apply these understandings to interpret, integrate and extend their knowledge.

4. Foundation 3 • Skills —Students will develop the skills required for scientific and technological inquiry, for solving problems, for communicating scientific ideas and results, for working collaboratively and for making informed decisions.

5. Foundation 4 • Attitudes—Students will be encouraged to develop attitudes that support the responsible acquisition and application of scientific and technological knowledge to the mutual benefit of self, society and the environment.

6. Ban Dihydrogen Monoxide • The Invisible Killer • Dihydrogenmonoxide is colorless, odorless, tasteless, and kills tens of thousands of people in the world every year. • Most of these deaths are caused by accidental inhalation of DHMO, but the dangers of dihydrogen monoxide do not end there. • Prolonged exposure to its solid form causes severe tissue damage. Symptoms of DHMO ingestion can include excessive sweating and urination, and possibly a bloated feeling, nausea, vomiting and body electrolyte imbalance. For those who have become dependent, DHMO withdrawal means certain death.

7. Dihydrogen monoxide: • Is also known as hydroxyl acid, and is the major component of acid rain. • Contributes to the "greenhouse effect”. • Contributes to the erosion of our natural landscape. • Accelerates corrosion and rusting of many metals. • May cause electrical failures and decreased effectiveness of automobile brakes. • Has been found in excised tumors of terminal cancer patients.

8. Contamination Is Reaching Epidemic Proportions! • Quantities of dihydrogen monoxide have been found in every stream, lake, and reservoir in Canada today. • But the pollution is global, and the contaminant has even been found in Antarctic ice. DHMO has caused millions of dollars of property damage in western Canada, the American midwest, and recently California.

9. Companies dump waste DHMO into rivers and the ocean, and nothing can be done to stop them because this practice is still legal. The impact on wildlife is extreme, and we cannot afford to ignore it any longer!

10. The Horror Must Be Stopped! • American and Canadian governments have refused to ban the production, distribution, or use of this damaging chemical due to its "importance to the economic health of this nation.” • In fact, the navy and other military organizations are conducting experiments with DHMO, and designing multi-billion dollar devices to control and utilize it during warfare situations. • Hundreds of military research facilities receive tons of it through a highly sophisticated underground distribution network. Many store large quantities for later use.

11. Should we be concerned? What should we do as world citizens to try and ban this substance?

12. Junk science  • DihydrogenMonoxide… is water! • But… Everything we just read about it… Is true! • Accidental Inhalation = Drowning 

13. Turning Lead Into Gold… • Can it be? • If it were true… What could I expect to find?

14. Proof- From a university! • Compare to a real university site!

15. Anne Marie Helmenstine, Ph.D. • Whenever you search for any question, most of the time you will come across an entry on About.com. • About.com is a site that earns its money from pageviews (that is how it attracts advertisers who pay for space) • One method they use for doing this is to pay “guides” to write about popular topics within a particular subject area. In other words… More important than “accurate” information is information that gets you to their site. • Further investigation (such as plugging her writing into anti-plagiarism software) leads to more questions about the authenticity of her information.

16. Organizing the Elements

17. Matter can be organized in several different ways: • Solid, liquid, gas, plasma • Pure substances (elements or compounds) • Mixtures (mechanical mixtures, solutions, suspensions, colloids).

18. A goal of many early chemists? • To organize elements in a meaningful way.

19. Back to biology • Review: Do you remember how early organizational systems classified biological diversity??!! • What is the modern classification system called? How is it organized?

20. It’s likely the classification system for elements has changed since the early days too? Think so? • Remember… Science is “self correcting”. • Remember the caloric theory from grade 7? • Advances in the classification approach for chemistry has revealed trends in the properties of known elements, and allowed scientists to predict the existence of elements not yet known.

21. Text says 112 elements… • Currently unnamed “ununpentium” is #115 • Element 115 will join its neighbors 114 and 116-flerovium and livermorium, respectively-on the periodic table just as soon as a committee from the International Union of Pure and Applied Chemistry decides on an official name. • An element's atomic number is the number of protons it contains in its nucleus.

23. 115 was actually created ten years ago, by a lab in Russia. Why are we just learning about its discovery? • When scientists find a new element, it has to be confirmed. • You need two different labs to confirm it before [IUPAC] considers adding it to the periodic table. A second lab had confirmed and repeated the same experiment, so now it's considered to be an official new element.

24. The way that you make new elements now is by shooting a beam of an element at another element and then seeing what happens when they collide. • Because new elements are so big, they're very unstable and fall apart extremely quickly.

26. If they fall apart extremely quickly-and clearly don't exist in nature-then what's the point? • Because they can! Scientists are basically “one upping” each other. • There's no way that a new, unstable element is going to have any uses because it deteriorates so quickly. • But it gives insight about the forces that hold atoms together so we can learn more about how the universe is held together.

27. This was a Human-made element. How do we know we've found all of the naturally occurring elements? • The good thing about elements is that they're defined by atomic numbers, meaning they're defined by the number of protons in the nucleus. • This number is never a fraction, so you can't have, for example, 3.2 protons in a nucleus. • So we know we have them all because we know of an element with one proton and an element with two protons and so on.

29. Looking for patterns… • Early chemists tried to group elements according to their properties, but this became confusing because different scientists organized them in different ways. • They used the symbols of the Sun and planets to represent the 7 metallic elements known at the time.

31. Definition of element that we use today was developed in late 1700s • Element: pure substance that cannot be broken down into any other substance; substance made up of only one type of atom. • By early 1800s 30 elements had been identified, including oxygen, lead, and mercury.

32. John Dalton • Made one of the first attempts to create a better system in the early 1800s. • Developed a new set of symbols for elements.

33. Jons Jacob Berzelius • Modified Dalton’s symbols. • Suggested using letters rather than pictures. The first letter of an element (capitalized) would become the symbol. • For elements with the same first letter, a small second letter would be added. • The new system allowed scientists to communicate in a precise and understandable manner.

34. An order that makes sense? • Listing elements in order of their increasing atomic mass. • Atomic mass is the mass of one atom of an element. • Scientists determined the average mass of an atom of other elements by comparing it with the mass of a carbon atom (12.0). • Atomic mass is measured by atomic mass unit (amu).

35. John Newlands • An English chemist, who in 1864 recognized a pattern when elements where arranged by increasing atomic mass. • He noticed that the properties of elements seemed to repeat through this list at regular intervals. • He called this pattern the “law of octaves”- similar to a musical scale. • Many scientists refused to accept the idea.

36. Dmitri Mendaleev • In 1869, a clearer understanding of how to arrange the elements emerged. • He collected the 64 elements known to exist (including lithium, carbon, nitrogen, oxygen, fluorine, sodium, silicon, phosphorus, sulfur, and chlorine). • He wrote down the properties of each element on a card (such as melting point, density, colour).

37. He sorted elements into a pattern based on their properties, and wanted to find a pattern that would allow him to predict the properties of elements not yet discovered. • Mendeleev was good at solitaire… And used his element cards like playing cards. • Eventually he found a pattern that seemed to work.

38. Properties of elements vary periodically with increasing atomic mass. • Mendeleev noticed gaps in his chart of the elements, but was convinced that his organization was correct. • He predicted that new elements would be discovered to fit into the gaps. • Many scientists disagreed and criticized him… But within 16 years the gaps were filled through the discovery of new elements that had the properties Mendeleev had predicted.

40. Check & Reflect • Page 121, 1-5, MAKE SURE you read pages 112-120 in your text. • Page 125, 1-7