Introduction to Atoms

Transcription

1 Introduction to Atoms Grade Six Science: Atoms, Molecules, and the Periodic Table of the Elements

2 1. What is the name and symbol of this element? I am an Alkali Metal. I have a single letter for my symbol. My symbol is the 11 th letter of the alphabet.

3 2. What is the name and symbol of this element? I am a Transition Metal. My atom is larger than Manganese, but smaller than Cobalt. I am in Group 8.

4 3. What is the name and symbol of this element? I am a Noble Gas. I am the heaviest of the Noble Gases. My atomic mass is not known for sure.

5 4. What is the name and symbol of this element? I am the most reactive Nonmetal. I am a gas at room temperature. I am in the same group as Iodine, but there is no other element in my group lighter than I am.

6 5. What is the name and symbol of this element? I am in the Other Metals. I have an atomic number of 80. I am a liquid at room temperature.

7 Matter Matter is anything that has mass and takes up space. It s that simple! Think about each of these things: -fire -carbon dioxide -lightning -the air we breathe -water or H2O Which, if any, are matter?

8 Elements Elements are defined as anything that cannot be broken down into other, smaller components. All of the atoms in an element have the same number of protons and electrons. Only a relatively small number of elements make up all the matter around us.

9 Atoms Atoms are the basic unit of any element. Any atom is made up of smaller particles called subatomic particles: Protons (Found in the nucleus) Electrons Neutrons (Found in the nucleus)

10 Protons, Electrons and Neutrons Protons (positive particles) have a + charge and are found in the nucleus (center) of the atom. Electrons (negative particles) have a - charge and are found outside and around the nucleus. Neutrons (neutral particles) have no charge and are found in the nucleus with protons.

11 A Model of a Carbon Atom KEY Proton (+) = Neutron = (no charge) Electron (-) =

12 Atomic Number An atom's atomic number of an element is the number of protons in the nucleus of one of its atoms. The atomic number indicates the place of an element in the periodic table of the elements. It also indicates the number of electrons that an element has, since atoms are neutral.

13 Periodic Table of the Elements The PTOTE is a chart, containing many facts about elements and their atoms Elements with similar properties are found in the same column or group. Elements in the same row have the same number of energy levels for their electrons.

14 Listed below are five elements in an incomplete Element Chart; please help me complete the chart. Name Symbol Atomic Atomic # of # of # of Mass Number Protons Electrons Neutrons Hydrogen 1 1 Oxygen 16 8 Sodium Neon Zinc 65 30

15 States of Matter Matter can exist in four phases (or states), solid, liquid, gas, and plasma plus a few other extreme phases, like critical fluids and degenerate gases. A solid is matter in which the molecules are very close together, cannot move around, but still are in motion. A liquid is matter in which the molecules are close together and move around slowly.

16 The Other Two States of Matter A gas is matter in which the molecules are widely separated, move around freely, and move at high speeds. A plasma is a gas that is composed of freefloating ions (atoms stripped of some electrons - positively charged particles) and free electrons (negative charges). A plasma conducts electrical currents.

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18 Methods of Changing Matter Matter can be changed or combined in three different ways, by : Physical mixture - in which the molecules remain unchanged but are moved around to form mixtures, solutions, and colloids (for example, water and salt form salty water and molecules of nitrogen, oxygen and other gases form air). Chemical reactions - which rearrange the atoms to form different molecules (for example, molecules of gaseous hydrogen can be combined with molecules of gaseous oxygen to form liquid water).

19 Covalent Bond Covalent Bond

20 Changing Matter Nuclear reactions - which rearrange and possibly transform subatomic particles to create different atoms (for example, fusion in the Sun's core, in which hydrogen nuclei are crushed together to form helium nuclei).

21 Supercritical Fluid A supercritical (or critical) fluid is a liquid/gas under extreme pressure. These supercritical fluids have unique characteristics, the density of a liquid and the mobility of a gas. Supercritical fluids exist deep inside some planets; for example, there is supercritical water deep inside the Earth.

22 Degenerate Gas A degenerate gas is one that is supercompressed and very dense. The molecules of this degenerate gas are virtually touching one another and the gas acts much like a solid. Unlike gases under normal conditions, the temperature in a degenerate gas does not depend on the pressure. These gases follow quantum mechanical laws.

23 A Scanning, Tunneling Electron Microscope: How The Tip of A STEM Works

24 Atoms in a Crystal: This is an image of silicon atoms arranged on a face of a crystal. The image came from a STEM.

25 Using a STEM to Study Atoms: Fe atoms on Cu arranged as a stadium

26 Using a STEM to Move and Manipulate Atoms: Carbon Atoms Arranged in a Unique Way

27 What is smaller than an atom? In the 1930s, it seemed that protons, neutrons, and electrons were the smallest objects into which matter could be divided and they were termed "elementary particles. Again, later knowledge changed our understanding as physicists discovered yet another layer of structure within the protons and neutrons. It is now known that protons and neutrons are made up quarks. Over 100 other "elementary" particles were discovered between 1930 and the present time. These elementary particles are all made from quarks and/or antiquarks. These particles are called hadrons. Once quarks were discovered, it was clear that all these hadrons were composite objects, so only in out-dated text books are they still called "elementary". Leptons, on the other hand, still appear to have no structure.

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29 Works Cited GIF of Solids Liquids Gases Plasma GIF of moving atom Growing Amethyst JPEG of STEM pic of silicon crystal

30 Works Cited, Continued JPEG STM5-CO molecules arranged on Pt JPEG STM15-Fe atoms on Cu Arranged as a stadium Picture of carbon atom and Picture of water molecule notes/chpt2/chpt2.htm Pic of how an STEM works