Topic 3 - Types Of Bonding Flashcards
What is an ion?
An atom or group of atoms that has gained or lost electrons to get a full outer shell.
Occurs between metals, loosing electrons, and non metals, gaining electrons.
What are cations?
Positively charged ions.
What are anions?
Negatively charged ions.
When would -ide be used in the end of a substance name?
When there is no oxygen combined in the negative ion.
When would -ate be used in the end of a substance name?
When there is oxygen combined in the negative ion.
What ions will form in group 1 atoms?
Loose 1 electron to form cations with one positive charge, +
What ions will form in group 2 atoms?
Loose 2 electrons to form cations with 2 positive charges, 2+
What ions will form in group 7 atoms?
Gain 1 electron to form anions with 1 negative charge, -
What ions will form in group 6 atoms?
Gain 2 electrons to form anions with two negative charges, 2-
What can ion formation be shown in?
Dot and cross diagrams.
What is the bonding of ionic compounds?
They are strong electrostatic forces of attraction between oppositely charged ions.
What is the structure of ionic compounds?
A lattice structure which has:
• A regular arrangement of ions
• Ionic bonds between oppositely charged ions
Why can ionic compounds only conduct electricity molten and in aqueous solution?
Ionic bonds are often soluble in water. Ionic compounds can dissolve to form aqueous solutions. The solutions can conduct electricity because the ions can move and carry the charge. This is not possible in solid form.
What are ionic compounds melting and boiling points like?
High
As a result, they are in a solid state at room temperature.
There are many strong ionic bonds so large amounts of energy must be transferred to the lattice structure to break these bonds.
What is a covalent bonds?
A pair of shared electrons between two atoms.
What are features of covalent bonds?
- Strong
- Form between non metal atoms
- Produces molecules, which can be elements or compounds
What are properties of simple molecular covalent substances?
- Weak intermolecular forces
- Low melting and boiling point because small amount of energy needed to overcome intermolecular forces
- Don’t conduct electricity because no mobile charge carriers e.g. electrons, ions
- Strong covalent bonds between atoms in molecule
Examples of simple molecular covalent substances?
Water - H2O Hydrogen Hydrogen chloride Methane Oxygen -O2 Carbon dioxide - CO2
What are properties of giant covalent substances?
- Each carbon has 4 covalent bonds
- Strong covalent bonds
- High melting and boiling point
- Does not conduct as nothing can move
- Regular lattice structure
What are examples of giant covalent substances?
Diamond
Graphite
They are different forms of carbon.
What are properties of diamond?
- It doesn’t conduct electricity, as it has no delocalised electrons
- Each carbon is bonded to four other carbons. This gives it a rigid structure making it very hard. Diamond is used in cutting tools.
What are properties of graphite?
- Each carbon is bonded to three other carbons giving each carbon one delocalised electrons.
- It conducts electricity due to delocalised electrons, so can be used as electrodes.
- Weak intermolecular forces mean layers slide over each other, which makes it suitable for use as a lubricant.
- Strong covalent bonds between atoms
What are properties of metals?
- High melting and boiling points
- Conduct electricity
- Malleable
- Shiny
- High density
What are properties of non-metals?
- Poor conductors of electricity and heat
* Low boiling and melting point
What does metallic bonding occur between?
Metals
High melting and boiling points because of strong electrostatic forces of attraction between positive metal ions and delocalised electrons
What is the structure of a metallic bond?
- Consists of a giant lattice of positively charged metal ions with a sea of delocalised electrons.
- Delocalised electrons come from the outer shells of the atoms
Why are metals malleable?
If a force is applied to a metal:
• Layers of positive ions slide over each other
• The metal changes shape without shattering
Most non-metals are brittle when solid, meaning that they shatter when force is applied.