Ions, Ionic Bonding and Covalent Structures Flashcards
What is an Ion?
Electrically charged particle formed when an atom or molecule gains or loses electrons.
What happens when metals form ions?
They lose electrons from their outer shell, to form positive ions.
What happens when non-metals form ions?
They gain electrons into their outer shell and form negative ions.
What happens when metal and non-metal react together?
The metal atom loses electrons to form a positively charged ion and non-metal gains these electrons to form negatively charged ions.
What is an Ionic Bond?
When oppositely charged ions are strongly attracted to one another by electrostatic forces.
What are group 1 and 2 elements?
Metals - so they lose electrons and form positive ions
What are group 6 and 7 elements?
Non-metals - so they gain electrons and form negative ions.
How can you use Group numbers to find out how many ions are gained or lost?
The group number IS the number of ions gained or lost.
e.g Group 1 (metals) become 1+ ions
Group 6 (non-metals) become 2- ions
How can you use Dot and Cross Diagrams?
They show the arrangement of electrons in an atom or ion, so they can be used to show the change in electrons in a reaction.
What is an Ionic Compound?
Is any compound which only contains ionic bonds
What are Ionic Lattices?
The regular arrangement of ions in an ionic substance, which have very strong electrostatic forces of attraction.
Name 3 properties of Ionic compounds?
1) High melting and boiling points, due to strong bonds
2) When solid, they cannot conduct electricity, when dissolved in water they can - due to ions separating and becoming free to move.
3) When they melt, ions are free to move, and therefore conducts electricity.
How can you use a 3D diagram of an Ionic Lattice, to find the formula of an Ionic Compound?
1) Use it to work out the Ions of the non-metal and metal
2) Balance the charges so they equal 0, this will give you the formula
e.g Potassium and Oxide Ions
1+ 2-
(2x1+) - 2- = 0
Therefore K2O - due to needing two potassium ions
to balance out oxide ions
What is a Covalent bond?
A bond between non-metals atoms formed when atoms share electrons to achieve a full outer shell of electrons.
Name the 3 ways can draw covalent bonds?
1) Dot and Cross - drawn in overlap and shows only outer shell
2) Display Formulas - shows covalent bonds a single lines between atoms
3) 3D models - shows the atoms, the covalent bonds and their arrangement in space next to each other.
What are simple molecular substances?
Simple Molecular Substances are made up of molecules containing a few atoms joined together by covalent bonds.
e.g Hydrogen or Chlorine
How do you show double or triple bonds in covalent bond display formula?
You add a line for each bond
e.g 1 line = 1 bond etc
Name 3 propities of Simple molecular substances?
1) They have very strong covalent bonds, however very weak forces of attraction between molecules.
2) Melting and Boling points low as you only need to break weak intermolecular forces.
3) Don’t conduct electricity due to not being charged and therefore no free electrons, and most molecular substances are gases or liquids at room temp.
