Bonding, Formulus and Equtions of Chemistry

Bonding, Formulas and Equations Bonding: A bond is formed when atoms shared or transfer a of electrons. Bonds are forces that hold 2 atoms together in a compound. When a bond if formed energy is Released When a bond is broken energy is Absorbed The more energy that is given off during the formation of a bond, the more stable the bond and the more stable the compound. Ex. Reaction 1 B+C BC + 100 kJ Reaction 2 X+YXY + 400 kJ XY is the more stable compound (Table I) 1. As energy is released during the formation of a bond, the stability of the chemical system generally (1) decreases 2 increases (3) remains the same 2. Which kind of energy is stored in a chemical bond? potential energy (3) activation energy (2) kinetic energy (4) ionization energy 3. Consider the reaction below. 2Na(s) + Cl2(g) → 2NaCl(s) As the reactants form products, the stability of the chemical system decreases increases (3) remains the same 4. When a chemical поп hydrogen atoms, the potential energy of the atoms (1) decreases (2) increases (3) remains the same 5. Energy is released when the atoms of two elements bond together to form a compound. Compared to the total potential energy of the atoms before bonding, the total potential energy of the atoms after bonding is (1) higher and the compound formed is stable (2) higher and the compound formed is unstable ③ lower and the compound formed is stable (4) lower and the compound formed is unstable Lewis Dot Diagrams: Consist of a chemical symbol surrounded by one to eight dots. These dots represent the valence e- Ex. Draw the Lewis dot diagrams for the following elements: K Al. S: F: Ne 6. Which electron dot diagram represents an atom of chlorine in the ground state? (1) C1: ( 2) (3) ::: 7. Atom X has an electron configuration of 2-8-2. Which electron dot diagram correctly represents this atom? Type of Bond Definition Also Called Characteristics Example Ionic Bond Formed by the transfer of one or more electrons from one atom to another - Results in ions Salts or Crystalline - High melting point
- Do not conduct electricity as solids, but do as liquids or dissolved in water
- Crystalline Structure
- Usually solids at room temperature NaCl
KF Експортувати в Таблиці Ionic bonds form between metals and non-metals and have high ED's (electronegativity difference). The greater the ED, the greater the ionic character of the bond. Ex. NaCl ED = 2.3 Ex. LiBr ED = 2.0 Which has the greatest ionic character? NaCl Ionic Lewis dot structures: Ex. KF [K]+[::F:]- Ex. Na₂O [Na]+[::O:]²- [Na]+ 8. When a calcium atom loses its valence electrons, the ion formed has an electron configuration that is the same as an atom of (1) Cl (2) Ar (3) K (4) Sc   9. The bond between which pair of elements is the least ionic in character? (1) H-F (2) H-Cl (3) H-Br (4) H-I 10. Which compound has the greatest degree of ionic character? (1) NaF (2) MgF₂ (3) AlF₃ (4) SiF₄ 11. Which compound in the solid state has a high melting point and conducts electricity when it is liquefied? (1) carbon dioxide (2) silicon dioxide (3) hydrogen chloride (4) potassium chloride   12. Which compound is described correctly? (1) BaCl₂ is covalent and molecular. (2) H₂O₂ is covalent and empirical. (3) H₂O is ionic and molecular. (4) NaCl is ionic and empirical. 13. Which element forms an ionic bond with fluorine? (1) fluorine (2) carbon (3) potassium (4) oxygen 14. What is the correct Lewis electron-dot structure for the compound magnesium fluoride? (A) [F:Mg:F:] (B) Mg:F: (C) Mg:F:F: (D) Mg:F: Which kind of energy is stored within a chemical bond? (1) free energy (2) activation energy (3) kinetic energy (4) potential energy   Which particles may be gained, lost, or shared by an atom when it forms a chemical bond? (1) protons (2) electrons (3) neutrons (4) nucleons   The forces between atoms that create chemical bonds are the result of the interactions between (1) nuclei (2) electrons (3) protons and electrons (4) protons and nuclei   At STP, potassium is classified as (1) metallic solid (2) a molecular solid (3) a network solid (4) an ionic solid The degree of polarity of a bond is indicated by (1) ionization energy difference (2) the shape of the molecule (3) electronegativity difference (4) the charge on the kernel   In a nonpolar covalent bond, electrons are (1) located in a mobile "sea" shared by many ions (2) transferred from one atom to another (3) shared equally by two atoms (4) shared unequally by two atoms   Which type of bond is formed when an atom of potassium transfers an electron to a bromine atom? (1) metallic (2) ionic (3) nonpolar covalent (4) polar covalent   When two atoms form a chemical bond by sharing electrons, the resulting molecule will be (1) polar only (2) nonpolar only (3) either polar or nonpolar (4) neither nonpolar nor polar   Which type of substance is soft, has a low melting point, and is a poor conductor of electricity? (1) covalent solid (2) ionic solid (3) metallic solid (4) network solid   Which statement is true concerning the reaction N₂(g) + N₂(g) → N₂(g) + energy? (1) A bond is broken and energy is absorbed. (2) A bond is broken and energy is released. (3) A bond is formed and energy is absorbed. (4) A bond is formed and energy is released.   Which electron dot formula represents a substance that contains a nonpolar covalent bond? (1) [Na]+ [::Cl:]- (2) H:H (3) :C:::C: (4) H:Ö:H   Which electron dot diagram represents a molecule that has a polar covalent bond? (1) :Cl:Cl: (2) H:H (3) H:Cl: (4) K+ [:Cl:]- When a sodium atom reacts with a chlorine atom to form a compound, the electron configuration of the ions forming the compound are the same as those in which noble gases? (1) krypton and neon (2) krypton and argon (3) neon and helium (4) neon and argon   Which atom will form an ionic bond with a Br atom? (1) N (2) O (3) Li (4) C A white crystalline salt conducts electricity when it is melted and when it is dissolved in water. Which type of bond does this salt contain? (1) ionic (2) metallic (3) nonpolar covalent (4) polar covalent   In which molecule is hydrogen bonding the strongest? (1) HF (2) HCl (3) HBr (4) HI Which statement correctly describes the bonds in the electron dot diagram shown below? (1) One of the bonds is ionic. (2) One of the bonds is metallic. (3) All of the bonds are covalent. (4) None of the bonds are covalent.