Bonding and properties of materials Flashcards
what is a group of atoms held together by covalent bonds called
a molecule
Which elements are diatomic
iodine, bromine, chlorine, fluorine, oxygen, nitrogen, hydrogen
what is an ionic bond
the force of attraction between a positively charged metal ion and a negatively charged non-metal ion
What charge is a metal ion
Positive, because it gains electrons
What charge is a nonmetal ion
Negative, because it gains electrons
What structure is an ionic compound
Lattice
What are the properties of ionic lattices
High melting and boiling points, solid at room temperature, conduct when molten or in solution
Why do ionic lattices only conduct when molten or in solution
Because the ions are free to move
What are the properties of covalent networks
Very high melting and boiling points, solid at room temperature, never conducts (except graphite)
What are the properties of a discrete covalent bond
Low melting and boiling points, liquid or gas at room temperature, never conducts
What is electrolysis
Electrolysis is the breaking up of an ionic solution using electricity
what is a covalent bond
a covalent bond is a shared pair of electrons between atoms of 2 non metal elements
Describe an experiment to show the effects of electrolysis
A beaker with an ionic solution (e.g. Copper chloride). Two electrodes suspended in the solution, one negative and one positive, both attached to a DC supply. (Copper will form on the negative electrode because it is a positive ion, chlorine gas will form around the positive electrode because it’s a negative ion)
