Chapter One: Atoms, Elements, and Compounds

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!

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?

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

.An Introduction to the Atom

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 thought to be the smallest units of matter, and they could not be divided.Later, it was found that there are subatomic particles that make up atoms, and therefore, atoms can be divided.What are these subatomic particles?The Structure of Atoms

The NucleusThe 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.

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!

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.

Subatomic Particles: ProtonsA 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.

Subatomic Particles: NeutronsA 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.

Subatomic Particles: ElectronsAn 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.Time for a good proton jokeA 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.Electron Behavior

Lets make some atoms...In your groups, use the items in your baggies to make an atom. Discuss your ideas on where the different subatomic particles go.

Why is this important???I know some of you might be asking that very question! Do you remember how many atoms we said were in a grain of sand yesterday?Our bodies, our world, all of science is made up of atoms, and atoms are made up of even smaller parts, and those even smaller parts are made up of even smaller parts.... You see where I am going with this.We must understand the smallest units of matter to get to the bigger ones like people, planets, stars, solar systems, galaxies, and the entire universe! An atom is like a...We may have switched to Science, but we cant forget about Writing and Language Arts!Thinks think about similes and metaphors. This will make it easier for you to remember where subatomic particles live in an atom.Here is an example:An atom is like a house with a big yard and a fence. The protons and neutrons are the people who live inside, the nucleus is the house itself, and the electrons are the fence surrounding the house. Time for some practiceFor 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.

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!

Answer!He isnt a drumstick at KFC because the bird is only touching the line, NOT the line and the ground. The bird would have to touch the line and the ground in order to create a complete circuit for the electricity to travel through.

Atomic NumberThe 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.IonsIons 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.IsotopesIsotopes 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.

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!

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.

Elements and Isotopes

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.Ions

Since you are so interested in nuclear reactions

Elements of MatterWhat are the properties of elements?Today, we will do an experiment to try and classify elements. Perform the experiment on pages E12 and E13Use the chart to record your observations of each substance.Classify the materials into two separate groups. I cant tell you what those groups will be!Answer questions 1-3 on page E13 on the back of the chart, but do not do 4 and 5. We will do that in class tomorrow. Complete this for homework due tomorrow!

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!

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.Classifying ElementsInto what two groups did you and your group determine you could classify these objects?What do all the metals have in common?What do all the non-metals have in common?Lets look at questions 4 and 5 together.Why do you think we performed this experiment?

The Elements of MatterWhat 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? How Elements are Formed

How elements are formedAs 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).Experiment Results: Metals vs. Nonmetals75% 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.Duh!

Time for a little practiceFor 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!

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!

Answer!

The Periodic TableLets get the bad news out of the way first You have a quiz over the Periodic Table next week.ButWe have a fun rap to help us with some of the elements http://www.youtube.com/watch?v=lDp9hUf_SV8&feature=related

Periodic Table HistoryThe 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 there 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. How to read the tableEach 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.

How to read an elementThis is cobaltWhat 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?

Time for some good jokesAnyone know any jokes about sodium?NaGold 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

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

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

Changes of StateTime for an experimentPerform the experiment on pages E20 and E21. Record the temperatures on the chart paper.Create a line graph showing the change in temperatureAnswer questions on lab sheet.Complete the line graph and questions for homework tonight!

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!

Answer!

Changes of state experimentLets talk about our experiment from yesterday. What conditions caused the temperature of your water to change?Why did some conditions not cause a change in temperature at all?How could we change our experiment to show drastic changes in temperature?

Forms of MatterWe 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: H2OWhat 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.States of MatterDo you know what the states of matter are?Solid- definite shapeLiquid- definite volume, but no definite shapeGas- no definite shape or volumeCan 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. A little more on the States of Matter

Physical Science: States of Matter

Science question of the day!Why do fingers and toes wrinkle in the bathtub?

Answer!

Characteristics of MatterSolids- 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. Changes of StateAs the chalkboard picture indicated yesterday, 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

Changes in StateThe 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 gas is called its boiling point.Pressure can also change state. For example, if a gas is compressed enough it can change to a liquid.Chemical CompoundsA compound is a substance formed of the atoms of two or more elements. We talked about H2O 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!Time for a little practiceFor homework tonight, read What Are Compounds, and answer questions 1-6.EFFORT!

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!

Answer!

Acids and BasesAcids 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.Uses of Acids and BasesWe 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.

Identifying Acids and BasesTime for an experimentComplete the experiment on the handout and complete the questionsthat go along with the experiment.- The results from your experiment will be due tomorrow!