C3- Structure and Bonding Flashcards
- State the three types of strong chemical bonds.
Ionic, covalent and metallic.
- In ionic bonds, what are the bonds formed between?
For ionic bonding the particles are oppositely charged ions.
- In covalent bonding, what are the bonds formed between?
For covalent bonding the particles are atoms which share pairs of electrons.
- In metallic bonding, what are the bonds formed between?
For metallic bonding the particles are atoms which share delocalised electrons
- Between which classes of elements do ionic bonds form?
Ionic bonding occurs in compounds formed from metals combined with non-metals.
- Between which classes of elements do covalent bonds form?
Covalent bonding occurs in non-metallic elements and in compounds of non-metals.
- Between which classes of elements do metallic bonds form?
Metallic bonding occurs in metallic elements and alloys.
- How does an ionic bond form?
- When a metal atom reacts with a non-metal atom electrons in the outer shell of the metal atom are transferred.
- Metal atoms lose electrons to become positively charged ions.
- Non-metal atoms gain electrons to become negatively charged ions.
- The ions produced by metals in Groups 1 and 2 and by non-metals in Groups 6 and 7 have the electronic structure of a noble gas (Group 0).
- The ionic bond is the result of the strong electrostatic attraction between the oppositely charged ions.
- Describe the characteristics of an ionic structure.
- An ionic compound is a giant structure of ions.
- Ionic compounds are held together by strong electrostatic forces of attraction between oppositely charged ions.
- The forces act in all directions in the lattice and this is called ionic bonding.
- Describe the characteristics of a covalent molecule or structure.
- When atoms share pairs of electrons, they form covalent bonds.
- These bonds between atoms are strong.
- Covalently bonded substances may consist of small molecules, such as H2, Cl2, O2, N2, HCl, H2O, NH3 and CH4.
- Some covalently bonded substances have very large molecules, such as polymers.
- Some covalently bonded substances have giant covalent structures, such as diamond and silicon dioxide.
- Describe the characteristics of a metallic structure.
- Metals consist of giant structures of atoms arranged in a regular pattern.
- The electrons in the outer shell of metal atoms are delocalised and so are free to move through the whole structure.
- The sharing of delocalised electrons gives rise to strong metallic bonds.
- State the three states of matter
The three states of matter are solid, liquid and gas.
- What are the transitions between states and where do they occur?
Melting and freezing take place at the melting point, boiling and condensing take place at the boiling point.
- What is the model that represents the three states of matter?
The particle model
- How does the particle model represent the three states of matter?
- In this model, particles are represented by small solid spheres.
- In solids, they are in a close packed, regular arrangement
- In liquids they are in a close packed, random arrangement.
- In gases, the particles are separate from each other.
- How is particle theory used to explain melting, boiling, freezing and condensing?
- The amount of energy needed to change state from solid to liquid and from liquid to gas depends on the strength of the forces between the particles of the substance.
- The nature of the particles involved depends on the type of bonding and the structure of the substance.
- The stronger the forces between the particles the higher the melting point and boiling point of the substance.
- What are the limitations of the particle model?
Limitations of the simple model include that there are no forces between the spheres, that all particles are represented as spheres and that the spheres are solid.
- How are the states of matter represented in a chemical equation?
In chemical equations, the three states of matter are shown as (s), (l) and (g), with (aq) for aqueous solutions.