1 / 14

Nature of Matter

Nature of Matter. All of the materials around you are made up of matter. You are made up of matter, as are the chair you sit on and the air you breathe. 1. Give an example of solid matter. 2. Give an example of liquid matter. 3. Give an example of gaseous matter. 4. Is all matter visible?

sadah
Télécharger la présentation

Nature of Matter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nature of Matter All of the materials around you are made up of matter. You are made up of matter, as are the chair you sit on and the air you breathe. 1. Give an example of solid matter. 2. Give an example of liquid matter. 3. Give an example of gaseous matter. 4. Is all matter visible? 5. Does all matter take up space?

  2. Nature of Matter Atom: the smallest unit of matter that cannot be broken downby chemical means. *consist of 3 kinds of particles: *Remember: all matter is made of ATOMS. • Protons (+) • Neutrons ( ) • Electrons (-) Nucleus (+) of an atom Travel around the nucleus making an Electron Cloud

  3. A T O M

  4. Element: a pure substance made of only ONE kind of atom. Cannot be broken down to other substances. More than 100 elements are known (92 naturally occuring). Only about 2 dozen are commonly found in nature. Each element is represented by a one or two letter symbol. * * * Examples of Elements: Gold (Au) Oxygen (O) Carbon (C) Copper (Cu)

  5. Element(cont.) • Atomic Number: number of protons 6 C Carbon 12.011

  6. Isotopes: Atoms of an element that have different numbers of neutrons Mass number: the sum of protons and neutrons in the nucleus. Isotopes are identified by their mass number. Atomic mass: weighted average of the masses of the elements isotopes. Nonradioactive carbon-12 Radioactive carbon-14 Nonradioactive carbon-13 6 electrons 6 protons 6 neutrons 6 electrons 6 protons 7 neutrons 6 electrons 6 protons 8 neutrons

  7. Isotopes (cont) Because they have the same number of electrons all isotopes of an element have the same chemical properties Some isotopes are radioactive, meaning that there nuclei are unstable and break down at a constant rate over time. This radiation can be dangerous. There are also important scientific and practical uses. & • Geologist can determine age of rocks by analyzing isotopes found in them. • Radiation from certain isotopes can be used to treat cancer and kill bacteria that cause food to spoil. • Can be used as labels or ‘tracers’ to follow the movements of substances within organisms. & &

  8. Compounds:a substance made up of two or more elements. Example of a compound: + Table salt (NaCl) = Sodium (Na) soft silver metal Chlorine (Cl) Poisonous gas The physical and chemical properties of a compound are usually very different from those of the elements from which it is formed.

  9. Chemical Bonds • There are two main types of chemical bonds. • Ionic: one or more electrons are transferred from one atom to another. • An atom that loses an electron has a positive charge. • An atom that gains an electron has a negative charge. • Positively and negatively charged atoms are called ions. • Covalent : two or more atoms share electrons • Covalent bonds produce molecules.

  10. Ionic Bonding Sodium atom (Na) Chlorine atom (Cl) Sodium atom (Na+) Chlorine atom (Cl-) Transfer of electron Protons +11 Electrons -11 Charge 0 Protons +17 Electrons -17 Charge 0 Protons +11 Electrons -10 Charge +1 Protons +17 Electrons -18 Charge -1

  11. Covalent Bonding

  12. Van der Waals Forces Some elements will attract electrons more than other elements. This unequal sharing of electrons can result in slightly charged (positive and negative) regions of a molecule. Van der Waal forces are the attraction of oppositely charged regions of nearby molecules. Van der Waals forces form between molecules on the surface of a gecko’s foot and molecules on the wall- allowing the gecko to balance the pull of gravity, and walk up vertical surfaces.

  13. Why study Chemistry? Why have a Chapter on Chemistry in Biology. *We are all living things. And we interact with other living and non-living things around us. *Chemical Reactions occur

More Related