Term

1. What is an isotope? → 2. Define matter. 3. What does ionization energy refer to? 4. What is an intramolecular bond? 5. Describe a covalent bond. 6. Difference between non polar and polar covalent bonds? → 7. Define electronegativity. 8. What characterizes an ionic bond? 9. Explain metallic bonding. 10. What are intermolecular forces? 11. Define heat of reaction (ΔH).. 12. What is an exothermic reaction? 13. What is an endothermic reaction?

Definition

1. Atoms of the same element that have different mass numbers (different numbers of neutrons). 2. → Any physical substance that possesses mass and occupies space. 3.→ The energy required to remove one mole of electrons from one mole of gaseous atoms, forming one mole of gaseous positive ions. 4. → A bond between atoms within the same molecule. 5.→ A sharing of at least one pair of electrons between two non metal atoms. 6.→ Non polar: equal sharing of electrons (zero electronegativity difference). Polar: unequal sharing due to a difference in electronegativity. 7.→ A measure of an atom’s tendency to attract a bonding pair of electrons. 8.→ Transfer of electrons to form cations and anions that are electrostatically attracted in an ionic crystal. 9.→ Attraction between positive metal cores and a “sea” of delocalised electrons. 10.→ Forces of attraction between separate molecules or between atoms of noble gases. 11.→ The net change in chemical potential energy of the system during a reaction. 12.→ A reaction that converts chemical potential energy into thermal energy (releases heat). 13.→ A reaction that converts thermal energy into chemical potential energy (absorbs heat).