C3-Structure And Bonding Flashcards
Which states of matter can flow?
Liquids and gases
Which states of matter are considered fluids?
Liquids and gases
What is the change of state called by which a solid changes directly to a gas without melting?
Sublimation
What are the limitations of the particle model?
-The particles aren’t solid (most of an atom is empty space)
-The particles aren’t spheres
-It doesn’t show the forces between particles so there is no way of showing how strong they are
Define a compound
A compound contains two or more elements that are are chemically combined
What holds ions together in ionic compounds?
Very strong electrostatic forces of attraction
Why do ionic compounds have high melting and boiling points?
To seperate the ions you have to overcome all the strong electrostatic forces of attraction acting in all directions
Why can’t a solid ionic compound conduct electricity?
Its ions are held in fixed positions in the lattice so it cannot carry the electrical charge
What are the two ways to make the ions in an ionic compound mobile?
-Melting the compound
-Dissolving the compound in water
What is covalent bonding?
Where atoms of non-metals share electrons with each other
What is ionic bonding?
Where a metal gives its electrons to a non-metal
Limitations of the 2D ball and stick model
Does not show the true shape of the molecule (shows the bonds at 90 degrees)
Limitations of the dot and cross model
-Shows electrons to be different whereas in reality all electrons are the same
-The electrons are in fixed positions but scientists believe that the electrons in covalent bonds are constantly moving
Why do simple molecules have low melting and boiling points?
There are weak intermolecular forces of attraction between molecules
Why can’t simple molecules conduct electricity?
They aren’t charged so there ae no free electrons or ions
