Science Question of the day!

1. Science Question of the day! • Would you weigh more or less on the moon than you do on earth? • Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

2. Answer! • The gravity on the moon is 1/6 of that of the earth; therefore, a person will weigh 1/6 of their weight on earth on the moon. That means I would weigh approximately 19 lbs. How much would you weigh?

3. Chapter One: Atoms, Elements, and Compounds The unleashed power of the atom has changed everything save our modes of thinking, and we thus drift toward unparalleled catastrophe.Albert Einstein .

4. An Introduction to the Atom

5. What is an atom? • Matter is made up of atoms. • How many atoms do you suppose are in this one grain of salt? • There are more than 2,000,000,000,000,000,000 (2 quintillion) atoms. • Atoms were though to be the smallest units of matter, and they cannot be divided. • Later, it was found that there are subatomic particles that make up atoms. • What are these subatomic particles?

6. The Structure of Atoms

7. The Nucleus • The nucleus is not a subatomic particle. • It is, however, the home of subatomic particles in an atom. • The nucleus is small, but it makes up almost 99% of the mass of the atom. • The nucleus is the center of the atom, and it contains a positive electric charge.

8. Subatomic Particles: Protons • A proton is a subatomic particle that has a positive electrical charge. • Each nucleus contains at least one proton. • Protons are made of even smaller particles called quarks. • There are over 100 subatomic particles, but we will only talk about three: protons, neutrons, and Electrons.

9. Time for a “good” Proton joke • A proton and a neutron are walking down the street. The proton says, "Wait, I dropped an electron help me look for it." The neutron says "Are you sure?" The proton replies "I'm positive.“ • HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA! • That was so funny.

10. Science Question of the day! • Why do stars twinkle? • Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

11. Answer! • Light reaches us after it is refracted through various layers of air. As light passes through the earth’s atmosphere, it is made to flicker by hot and cold ripples of air. This is what makes it seem like it is twinkling. It would be like looking at light through heat waves off the road in the summer. The image is somewhat distorted because of the movement of the air.

12. Subatomic Particles: Neutrons • A neutron is a subatomic particle that has the same mass as a proton, but no electrical charge. • Neutrons are also found in the nucleus with the protons.

13. Subatomic Particles: Electrons • An electron is a negatively charged subatomic particle. • They are constantly moving around the nucleus. • They are much smaller than neutrons and protons. • Electrons exist in a cloud around the nucleus. • This cloud makes up the borders of the atom.

14. Electron Behavior

15. Time for some practice… • For homework tonight, you will read “What Are Atoms” and complete questions 1-6 for homework. • We will check this tomorrow! Remember, I care more about effort than I do about having all the right answers.

16. Science question of the day! • Why aren’t birds electrocuted when they sit on power lines? • Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

17. Answer! • He isn’t a drumstick at KFC because the bird is only touching one line. The bird would have to touch two lines in order to create a complete circuit for the electricity to travel through.

18. Atomic Number • The number of protons in an atom is called the atomic number. • For example, any atom with only one proton is called a hydrogen atom. Any atom with eight protons is called an oxygen atom. • Why is this important? • The atomic number is important because it tells us what family of elements the atom belongs to. • This will become more important in the next part of the chapter.

19. Ions • Ions are a special kind of atom that have either more or fewer electrons than protons. • This happens both in nature and in laboratories when atoms undergo a large amount of radiation or are subjected to mass amounts of energy all at once. • Ions are necessary in our chemistry.

20. Isotopes • Isotopes are atoms that have the same number of protons, but a different number of neutrons. • Neutrons help add to the mass of the atom, and if an atom has more neutrons it will weigh slightly more than an atom that has few.

21. Science question of the day! • Why is the sky blue? • Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

22. Answer! • Violet and blue light have short waves which are scattered more than red light waves. While red light goes almost straight through the atmosphere, blue and violet light are scattered by particles in the atmosphere. Thus, we see a blue sky.

23. Elements and Isotopes

24. What holds an atom together? • You might initially think that gravity holds atoms together. • Electrical charges hold the atom together. Opposites attract! Just like magnets. • Like magnets, like charges repel each other. • Let’s try it with magnets to see what’s going on in an atom. • But wait! There is a strong nuclear force at work here that is holding the atom together. It overcomes the repulsion of the charges. • Without it, our universe would collapse.

25. Ions

26. Since you are so interested in nuclear reactions…

27. Elements of Matter • What are the properties of elements? • Today, we will do an experiment to try and classify elements. • Perform the experiment on pages E12 and E13 • Use the chart to record your observations of each substance. • Classify the materials into two separate groups: metals and nonmetals. • Answer questions 1-3 on page E13 on the back of the chart. • Complete this for homework due tomorrow!

28. Science question of the day! • How does sunscreen work? • Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

29. Answer! • Sunscreen works by combining organic and inorganic active ingredients. Inorganic ingredients like zinc oxide or titanium oxide reflect or scatter ultraviolet (UV) radiation. Organic ingredients like octyl methoxycinnamate (OMC) or oxybenzone absorb UV radiation, dissipating it as heat. Some sunscreens protect us from the two types of damaging UV radiation: UV-A and UV-B. Both UV-A and UV-B cause sunburns and damaging effects such as skin cancer.

30. The Elements of Matter • What is an element? • An element is a pure substance that’s made up of only one kind of atom. • Elements cannot be broken down into different substances. • There are 90 known elements that occur in nature, and 22 have been created in a laboratory for a total of 112 elements. • Did you know that all natural elements are born from the death of a star?

31. How Elements are Formed

32. How elements are formed • As you learned from the video, only hydrogen and small traces of other elements existed at the beginning of the universe. • Through a process called fusion, subatomic particles join to create new elements. • Most elements exists in the solid state at room temperature, but some exist as gases (oxygen, helium, hydrogen, etc.), and some exist as liquids (mercury, bromine).

33. Experiment Results: Metals vs. Nonmetals • 75% of elements on earth are metals. • You can determine metals from nonmetals using specific properties. What properties do you think we use? • Fun Fact: One property we did not use in our experiment was heat conduction. Metals are great conductors of heat and electricity. That is why you shouldn’t stand under an umbrella in a thunder storm.

34. Duh!

35. Time for a little practice… • For homework tonight, read “What Are Elements”, and complete questions 1-6 for homework. • Remember, I care more about your effort than whether or not your answers are correct!

36. Science question of the day! • What are the northern lights? • Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

37. Answer!

38. The Periodic Table • Let’s get the bad news out of the way first… You have a quiz over the Periodic Table one week from today. • But… • We have a fun rap to help us… • http://www.youtube.com/watch?v=lDp9hUf_SV8&feature=related

39. Periodic Table History • The periodic table did not always look the way it does now. • In 1869 Dmitri Mendeleev placed elements into a table based on their atomic masses. • He noticed their properties fell into repeating patterns, but their were gaps in the patterns. • He hypothesized that the gaps should be filled with elements that had yet to be discovered. • He was correct! • The table was later organized by atomic number rather than mass.

40. How to read the table • Each square represents an element. • Each square contains the element’s atomic number, chemical symbol, name, and atomic mass. • The colors identify whether the element is a solid liquid or gas at room temperature. • Open your books to pages E16 and E17. • What do the colors mean? • Color also identifies natural vs. man-made elements.

41. How to read an element This is cobalt What is it’s symbol? What is cobalt’s atomic weight/mass? What is it’s atomic number? Pretend the color is dark yellow. What does it’s color tell us?

42. Time for some “good” jokes • Anyone know any jokes about sodium? • Na • Gold walks up to the basketball court and says , “Hey, can I play?” • Helium replies, “Au! Get our of here!” • Making good chemistry jokes is hard because all the good ones Argon. • I crack myself up…

43. Families of Elements • Families of elements usually have the same characteristics. • Families are in columns. • Column 1: metals that react strongly with other elements • Column 2: metals that react less strongly but burn brightly when heated • Columns 3-14: common metals that do not react strongly at all • Columns 15-17 in a stair-step: nonmetals (react strongly with metals from column 1) • Column 18: Noble gases (hardly react at all)

44. Time for a little practice… • For homework tonight, read “The Periodic Table”, and complete questions 1-5. • Remember, I care more about effort!

45. Changes of State • Time for an experiment… • Perform the experiment on pages E20 and E21. • Record the temperatures on the chart paper. • Create a line graph showing the change in temperature • Answer questions 1-3 on page E21. • Complete the line graph and questions for homework tonight due tomorrow!

46. Forms of Matter • We have learned that elements are only made of one kind of atom. • However, atoms can join together to form molecules. • They can be atoms of different elements, such as the molecular formulation for water: H2O • What do you think this formula means? • Molecules form when electrons in two or more atoms are attracted to the nuclei of both atoms. • The atoms act and move as a single particle: a molecule.

47. States of Matter • Do you know what the states of matter are? • Solid- definite shape • Liquid- definite volume, but no definite shape • Gas- no definite or volume • Can you think of a molecule that can exist in all three states? • Did know there is one more state of matter? • Plasma- composes nearly all the matter in the universe; contains no electrons, so it is able to move freely; stars, like our sun, are made of plasma! Lightning, neon signs, and fluorescent light bulbs are also made from plasma.

48. A little more on the States of Matter

49. Physical Science: States of Matter

50. Characteristics of Matter • Solids- Molecules are held tightly together and do not have freedom of movement. They do not move from their fixed positions. • Liquids- Molecules are not held in fixed positions. They are close together, but they have freedom of movement. • Gases- Molecules are father apart and can drift away from one another. Gases, unlike liquids and solids, can be compressed easily.