1 / 17

Introduction to Chemical Bonding

Introduction to Chemical Bonding. Chemical Reactions:. During chemical reactions, elements combine , rearrange , or break apart with others to form new substances . New substances are created when chemical bonds are broken or created. New Substance. Original Substance. Magnesium Oxide.

samuelhargrove
Télécharger la présentation

Introduction to Chemical Bonding

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. Introduction to Chemical Bonding

  2. Chemical Reactions: • During chemical reactions, elements combine, rearrange, or break apart with others to form new substances. • New substances are created when chemical bonds are broken or created. New Substance Original Substance Magnesium Oxide Chemical Reaction http://jchemed.chem.wisc.edu/JCESOFT/CCA/CCA3/STILLS/MAGAIR/MAGAIR/64JPG48/6.JPG http://www.bcscience.com/images/magnesium_burn.jpg Magnesium Metal http://www.polmag.pl/en/media/magnesium.jpg

  3. Evidence of Chemical Reactions: • Fire/Burning • Color change without dye • New gas created • Heat released • Heat absorbed http://amazingrust.com/Experiments/background_knowledge/Images/Fire-big.jpg http://z.about.com/d/chemistry/1/G/5/a/demonstration.jpg http://static.howstuffworks.com/gif/cold-pack.jpg http://en.wikipedia.org/wiki/Self-heating_can http://www.uncp.edu/home/mcclurem/ptable/ca_2.jpg

  4. Compounds are more than one kind of element joined together. Octet Rule: Describes how chemical bonds happen. • Atoms want a full valence (or outer electron energy level). • Full valence will mean having 8 valence electrons. http://www.chemprofessor.com/periodicqm_files/image005.gif

  5. Why are these atoms negative? Gaining electrons (and electrons are negative) means more negative charge than positive charges (protons). Octet Rule … It is easier for the atom to gain 1, 2 or 3 electrons rather than losing 5, 6 or 7. • To reach full valence, some atoms “want” to lose electrons and others “want” to gain electrons. • Atoms with FEWER than 4 valence electrons will bond by losing those electrons. • These atoms will become positively charged! • Atoms with MORE than 4 valence electrons will bond by gaining electrons (up to eight). • These atoms will become negatively charged! • Atoms with 4 valence electrons can gain or lose electrons. It depends on the element to which it is bonding. It is easier for the atom to lose 1, 2 or 3 electrons rather than gaining 5, 6 or 7. Why are these atoms positive? Losing electrons (and electrons are negative) means more protons (positive charge) than negative charges.

  6. A chemical bond is created by the sharing or exchange of electrons between elements. Example: Sodium (Na) • Valence? 1 • Easiest way to follow Octet Rule? Lose 1 electron • If following Octet Rule, what’s the charge? +1 http://www.historyforkids.org/scienceforkids/chemistry/atoms/pictures/sodium.jpg

  7. Example: Fluorine (F) • Valence? 7 • Easiest way to follow Octet Rule? Gain 1 electron • If following the Octet Rule, what’s the charge? –1 http://www.bbc.co.uk/schools/gcsebitesize/science/images/diag_fluorine.gif

  8. What will happen if Sodium and Fluorine atoms are mixed? • Electrons could transfer between the atoms. • A sodium atom could lose an electron to a fluorine atom. • Both atoms are left with full valence & are bonded together, creating a compound.

More Related