Topic 1 Flashcards
What are ions?
Ions are charged particles that can be single atoms or groups of atoms.
Why do atoms form ions?
To gain a full outer shell.
What happens when an atom gains electrons?
It forms negative ions (anions)
What happens when an atom loses electrons?
It forms positive ions (cations)
What are group 1 and 2 elements and what are their charges?
They are metals
Group 1 forms 1+ ions
Group 2 forms 2+ ions
What are group 6 and 7 elements and what are their charges?
They are non-metals
Group 6 forms 2- ions
Group 7 forms 1- ions
What do these elements have in common?
They form ions most readily
What is an ionic bond?
When a metal and a non-metal transfer electrons so the metal loses atoms (cation) and the non-metal gains electrons (anion) to gain a full outer shell. They are strongly attracted to each other by electrostatic forces.
What structures do ionic compounds have?
Giant ionic lattice structures with very strong electrostatic forces of attraction between oppositely charged ions.
Why do ionic compounds have high melting and boiling points?
Due to the strong attraction between the ions, it takes a large amount of energy to overcome it.
Why don’t solid ionic compounds conduct electricity?
The ions are fixed in place and can’t move. However when they melt, the ions are free to move and will carry an electric current.
Some also dissolve in water easily.
What are the advantages and disadvantages of 2D representations of structures?
They are simple and good at showing what atoms something contains and how the atoms are connected but don’t show the shape of the substances or the size of the atoms.
What are the advantages and disadvantages of dot and cross diagrams?
Useful for showing how compounds and molecules are formed and where the electrons in bonds/ions come from but don’t show size of atoms/ions or arrangement.
What are the advantages and disadvantages of 3D models of ionic solids?
Show arrangement of ions but only show outer layer of substance.
What are the advantages and disadvantages of ball and stick models?
They’re good helping visualise structures
They’re more realistic than 2D drawings
Though they have big gaps between the atoms but in reality this where the electron clouds interact.
They don’t show correct scales of ions or atoms