1 / 15

Ionic Compounds

Ionic Compounds. Forming Ions. Ion: A charged atom When an atom loses or gains an electron, it becomes charged When an atom loses an electron, it becomes positively charged ( cation ) since it now has more protons than electrons

maude
Download Presentation

Ionic Compounds

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. Ionic Compounds

  2. Forming Ions • Ion: A charged atom • When an atom loses or gains an electron, it becomes charged • When an atom loses an electron, it becomes positively charged (cation) since it now has more protons than electrons • When an atom gains an electron, it becomes negatively charged (anion) since it now has more electrons than protons

  3. An ion's charge is equal to the sum of its protons and electrons • Example Na1+: Sodium ion has 11 protons and 10 electrons • The periodic table shows the charges each element can have

  4. Ionic Bonds • Compounds consist of two or more different elements chemically linked together - These links are called chemical bonds • Ionic Bond: A type of chemical bond formed by the attraction between oppositely charged ions • **WHEN AN IONIC COMPOUND FORMS, ONE OR MORE ELECTRONS FROM ONE ATOM ARE TRANSFERRED TO ANOTHER ATOM** • An ionic bond forms between two oppositely charged ions creating a neutral compound • By forming an ionic compound, the loss and gain of valence electrons allows each ion to have a full outer energy level of electrons

  5. Recognizing Ionic Compounds • Ionic compounds are composed of a metal and a non-metal • Atoms of metals lose electrons to form cations (+), while non-metals gain electrons to form anions (-) • Sodium (group 1 alkali metal) loses an electron to form Na+ • Chlorine, a halogen in group 17, gains an electron to form Cl-

  6. Sodium fluoride is another example of an ionic compound [Na]+[F]- • NaF is found in toothpaste, fluoride strengthens tooth enamel and reduce cavities • Most Canadian cities add fluorine to drinking water to reduce cavities: Is this safe? • Too much fluorine can cause cancer, fragile bones and affect brain development in children

  7. Properties of Ionic Compounds • Ionic bonds are strong - they require a large amount of energy to break them Physical States • Most ionic compounds exist as solids in a crystal lattice - which is a regularly repeating pattern of ions

  8. Most ionic compounds are solids at room temperature • Most have high melting points (NaCl 801 ºC)

  9. Solubility • Most ionic compounds are soluble in water • Water separates the positive and negative ions causing ionic bonds to break • Many biological processes depend on dissolved ions (nerve impulses require Na+ and K+) • Dissolved ions are called electrolytes - when you sweat, you lose both water and electrolytes (many sport drinks are salty to replace these ions) • Ionic compounds are also used as fertilizers: ammonium nitrate (NH4NO3), ammonium phosphate (NH4)3PO4 and potassium chloride (KCl) • These fertilizers are soluble in water and absorbed by plant roots

  10. Conductivity • Any substance whose charged particles (electrons or ions) are free to move around is a good conductor of electricity • Metals are good conductors since their electrons are free to move • In the liquid state (melted or dissolved in water), ionic compounds are good conductors • In the solid state, ionic compounds are poor conductors since ions are locked in place in a crystal lattice • Pure water is a poor conductor, however, salt water is a good conductor

  11. Road Salt • NaCl lowers the freezing point of water and helps prevent ice forming on roads • Road salt is harmful since animals come to the road to lick the salt • Road salt causes cars and bridges to rust faster

  12. Harmful effects of road salt on the environment • Road salt enters the soil, ground water and surface water (lakes, rivers and streams) • High levels of salt reduces plant growth and is toxic to animals

More Related