Structure and Bonding Flashcards
What type of bonding occurs between metals and non-metals?
Ionic
What type of bonding occurs between non-metals?
Covalent
What type of bonding occurs between metals?
Metallic
What type of bonding occurs in sodium chloride?
Ionic
What type of bonding occurs in carbon dioxide?
Covalent
What type of bonding occurs in sodium?
Metallic
What is an ionic bond?
Electrostatic attraction between positive metal ions and negative non-metal ions
What is a covalent bond?
The sharing of electrons between non-metals
What is a metallic bond?
Electrostatic attraction between positive metal ions and negative electrons
What structure are ionic compounds?
Ionic lattice
Describe three properties of ionic compounds
High melting and boiling points, do not conduct electricity, solid at room temperature
Why do ionic compounds have high melting and boiling points?
Ions are held together by very strong bonds, which need a lot of energy to break
Why do ionic compounds not conduct electricity?
Ions are held in fixed positions and cannot move
When do ionic compounds conduct electricity?
When dissolved or molten
What are the properties of small covalent substances?
Usually gas or liquid at room temperature, low melting and boiling points
Why do small covalent substances have low melting or boiling points?
Weak intermolecular forces between molecules, which do not need much energy to overcome
What are the properties of giant covalent substances?
High melting and boiling points, do not conduct electricity
Why do giant covalent substances have high melting and boiling points?
Atoms are held together by very strong bonds, which need a lot of energy to break
Which giant covalent substance is the only one to conduct electricity?
Graphite
Why do covalent substances not conduct electricity?
There are no free electrons to carry the charge
What is a polymer?
A large molecule containing a repeating unit called a monomer
Why do polymers have high melting and boiling points?
Atoms are held together by very strong bonds, which need a lot of energy to break
What is a delocalised electron?
An electron which is not held in an atomic shell, is free to move around
What are three properties of metals?
High melting and boiling points, conducts electricity, malleable
Why are metals malleable?
Layers of atoms are able to slide over each other
Why do metals have high melting and boiling points?
Strong attraction between positive metal ions and negative electrons requrie a lot of energy to overcome
Why do metals conduct electricity?
Delocalised electrons can move and carry the charge
What is an alloy?
A mixture of two or more substances, one of which must be a metal
Why are alloys stronger than pure metals?
The layers of atoms are distorted by the different sized atoms, these layers do not slide over each other easily
Describe what happens to a metal atom and a non-metal atom when an ionic bond forms
Metal atoms lose electrons to become a positive ion. Non-metals gains electrons to become a negative ion.
Describe what happens when one chlorine atom forms a bond with another chlorine atom
An electron from each atom is shared so that each atom has a complete outer shell of electrons
Explain why most polymers are solid at room temperature
The atoms within polymer molecules are held together by strong covalent bonds. The intermolecular forces between the large polymer molecules are also quite strong
