chemistry review atoms, elements & isotopes. how big is an atom?

Download Chemistry Review Atoms, elements & Isotopes. How Big is an Atom?

If you can't read please download the document

Post on 30-Dec-2015

212 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • Chemistry Review

    Atoms, elements & Isotopes

  • How Big is an Atom?

  • How Many Cuts?Cut 114.0 cm5.5"Child's hand, pocketsCut 27.0 cm2.75"Fingers, ears, toesCut 33.5 cm1.38"Watch, mushroom, eyeCut 41.75 cm.69"Keyboard keys, rings, insectsCut 6.44 cm.17"Poppy seedsCut 81 mm.04"Thread. Congratulations if your still in!Cut 10.25 mm.01"Still cutting? Most have quit by nowCut 12.06 mm.002"Microscopic range, human hairCut 14.015 mm.006"Width of paper, microchip componentsCut 181 micron.0004"Water purification openings, bacteriaCut 19.5 micron.000018"Visible light wavesCut 24.015 micron.0000006"Electron microscope range, membranesCut 31.0001 micron.0000000045"The size of an Atom!

  • Atoms

    A. the basic unit of matter B. matter is anything that takes up space andhas massC. all things are made of atomsD. microscopic need special microscope to view1. 100 million atoms lined up in a row would only measure 1 cm long

  • E. Atomic Structure/componentsSubatomic particles:a. protons 1- positive charge 2- mass weight 1.0073 b. neutrons 1- no charge 2- mass weight 1.0087 c. electrons 1- negative charge 2- mass weight 0.000549

    All atoms have the same amt of protons and electrons Atomic number - # of protonsAtomic Mass - #p + #n

  • You can see an atom with your eyes?TrueFalse

  • An atom has weightTrue False

  • Which subatomic particle is located outside the nucleus of an atom?ElectronNeutronProton

  • The positively charged particle in an atom theElectronNeutron Proton

  • Protons and ______ are found inside the nucleus.ElectronsNeutrons Protons

  • The negatively charged particle in the atom is theElectronProtonNeutron

  • Which combination of particle and charge is correct?Proton: negative chargeElectron: positive chargeNeutron: negative chargeNeutron: no charge

  • II. Elements & Isotopes A. Element is a substance that cannot be broken down B. Elements are made up of lots and lots of the same kind of atom C. more than 100 elements known 1. represents with a single or 2 letters D. only about 2 dozen in living organisms 1. examples Ca, O, H, C, N, P, K, S, Na, Li, Zn, Mg, Cu, Fe, Se, I, F Co, Al, Si, Br, Ar, Mn, Sr, Pb, V E. Essential Elements of Life: C H N O P S Ca K

  • F. Isotopes 1. atoms of the same element that have differ masses due to the differ number of neutrons on the nucleus a. example: Carbon -12 ; Carbon -13; Carbon 14 b. all isotopes have the same chemical properties

  • G. Radioactive Isotopes 1. isotopes that give off radioactivity and have unstable nuclei 2. these isotopes break down at a consist rate after a period of time 3. although very dangerous, can be helpfula. Aging Fossils/Rocks b. Treat cancer c. Radioactive tags trace substances d. PET scan (CT scan)

  • III. Compounds

    A. a substance made of 2 or more elements 1. example H2O

    B. held together by chemical bonds

    C. main types: - ionic- covalent bond- hydrogen - van der waals

  • Isotopes weight the same.True False

  • Radioactive isotopes are goodTrue False

  • Two or more different atoms are combined to form a SymbolElementIsotopeCompound

  • In which if the following way do isotopes of the same element differ?In number of neutrons onlyIn number of protons onlyIn number of protons & massIn number of neutrons & mass

  • D. Ionic bonds 1. formed when 1 or more electrons are transferred from 1 atom to another a. opposite charges attract to form an ionic bond (Na(+)) (Cl(-)) b. when atoms lose electrons, the atoms becomes positive c. when atoms gain electrons, they become negative 2. when an atom becomes positively or negatively charged, they become known as ions a. if positively charged known as cation b. if negatively charged known as anion

  • E. Covalent bonds

    1. forms when electrons are shared between atoms 2. Two types a. polar covalent1- unequal sharing due to size differences 2- example: H2O b. nonpolar covalent 1- equal sharing of electrons

  • F. Hydrogen BondsHydrogen bond is the weak attraction between + of H and - of O or N of a different molecule

  • G. Van der Waals Interactions 1. Electrons move creating weak positive and negatively charged regions (even if non- polar) 2. named after the scientist 3. can hold even large molecules together 4. geckos show this force a. climbing up the smoothest surface, geckos can hold on even with 1 toe b. a gecko foot is covered w/ half million projections

  • c. the projections are dived into 100s of tiny flat fibers designed to come onto contact with a surface at the molecular level

    d. van der waals forces form btwn the surface molecules and the gecko foot

    e. when a gecko wants to move it peels its foot off at angle then reapplies it elsewhere on the surface

  • A covalent bond is formed byTransferring of electronsSharing electronsLosing electronsGaining electrons

  • Ionic bonds are formed whenTransferring of electronsSharing electronsLosing electronsGaining electrons

  • The gecko is an example of Covalent bondsIonic bondsHydrogen bondsVan der Waals forces

  • When an atom loses electrons it becomes a ______ ionPositively chargeNegatively chargedNeutral

  • There are three types of covalent bondsTrue False

  • Polar covalent is the unequal sharing of electronsTrue False

  • IV. Representing AtomsA. Bohr Model (e cloud)Use element or # protons/neutrons in nucleusSurrounding by energy shells w/e a. 2 electrons in first shell b. 8 electrons in 2nd c. 18 electrons in 3rd shells

  • B. Lewis Dot Structures 1. Use element symbol 2. Use dots to represent 3. valence electrons only

  • The Bohr Model shows how many electrons the element hasTrueFalse

  • The Lewis dot model shows all electrons an element hasTrueFalse

  • QuestionsASSIGNMENT:

    Review questions

    ************************************

View more >