Slide 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!

Slide 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?

Slide 3

The unleashed power of the atom has changed everything save our modes of thinking, and we thus drift toward unparalleled catastrophe. Albert Einstein Albert Einstein.

Slide 4

An Introduction to the Atom

Slide 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?

Slide 6

The Structure of Atoms

Slide 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.

Slide 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.

Slide 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. HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA HAHAHAHAHAHAHAHAHAHAHAHAHAHA! That was so funny.

Slide 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!

Slide 11

Answer! Light reaches us after it is refracted through various layers of air. As light passes through the earths 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.

Slide 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.

Slide 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.

Slide 14

Electron Behavior

Slide 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.

Slide 16

Science question of the day! Why arent 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!

Slide 17

Answer! He isnt 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.

Slide 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.

Slide 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.

Slide 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.

Slide 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!

Slide 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.

Slide 23

Elements and Isotopes

Slide 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. Lets try it with magnets to see whats 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.

Slide 25

Ions

Slide 26

Since you are so interested in nuclear reactions

Slide 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!

Slide 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!

Slide 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.

Slide 30

The Elements of Matter What is an element? An element is a pure substance thats 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?

Slide 31

How Elements are Formed

Slide 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).

Slide 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 shouldnt stand under an umbrella in a thunder storm.

Slide 34

Duh!

Slide 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!

Slide 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!

Slide 37

Answer!

Slide 38

The Periodic Table Lets 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

Slide 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.

Slide 40

How to read the table Each square represents an element. Each square contains the elements 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.

Slide 41

How to read an element - This is cobalt - What is its symbol? - What is cobalts atomic weight/mass? - What is its atomic number? - Pretend the color is dark yellow. What does its color tell us?

Slide 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

Slide 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)

Slide 44

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

Slide 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!

Slide 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: H 2 O 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.

Slide 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.

Slide 48

A little more on the States of Matter

Slide 49

Physical Science: States of Matter

Slide 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.

Slide 51

Changes of State As the chalkboard picture indicated earlier, matter can change its state of being when energy is applied. When energy is added (like heat) the molecules move faster and faster. With enough energy, a solid can change to a liquid, and a liquid can change to a gas. Lets look at my example

Slide 52

Changes in State The temperature at which matter changes varies based on the substance. The temperature at which a substance changes from a solid to a liquid is called its melting point. The temperature at which a substance changes from a liquid to a solid is called its freezing point. The temperature at which a substance changes from a liquid to a has is called its boiling point. Pressure can also change state. For example, if a gas is compressed enough it can change to a liquid.

Slide 53

Science question of the day! What causes the sound of thunder? Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

Slide 54

Answer!

Slide 55

Chemical Compounds A compound is a substance formed of the atoms of two or more elements. We talked about H 2 O earlier, this is a compound of two hydrogen molecules and one oxygen molecule. This is a chemical formula. The two means there are two hydrogen molecules. There is no number after the O because there is only one oxygen molecule. Compounds can also be made when a chemical reaction takes place. Like rust on a nail, for example!

Slide 56

Time for a little practice For homework tonight, read What Are Compounds, and answer questions 1-6. EFFORT!

Slide 57

Science question of the day! Why dont I fall out of a roller coaster when it goes upside down? Dont say because of my seatbelt or harness! Write the question and the answer in your science notebook. Be sure to explain your reasoning and use complete sentences!

Slide 58

Answer!

Slide 59

Acids and Bases Acids are compounds that react easily with other substances. Bases are compounds that also react easily with other substances. Acids and bases are on two opposite ends of a scale known as the pH scale. The scale goes from 0-14, with acids falling between 0-7 and bases falling between 7-14. 0 is the strongest acid, and 14 is the strongest base. Water has a pH of 7. It is a neutral substance as are all substances with a pH of 7. All substances fall somewhere on the pH scale. When mixed, equally strong acids and bases can neutralize one another.

Slide 60

Uses of Acids and Bases We have hydrochloric acid in our stomachs to digest food. Acids are used in fertilizers. Bases are used to create cement. Acids and bases are both used to develop pictures.

Slide 61

Identifying Acids and Bases Time for an experiment Complete the experiment on the handout and complete the questions that go along with the experiment. - The results from your experiment will be due tomorrow!