CC5 Flashcards
(28 cards)
What are bonds?
Forces of attraction that hold atoms together.
What are the most stable atoms and why?
The most stable atoms are those of the noble gases as they have a full outer electron shell.
What are ions?
Charged particles.
What are cations and how are they formed?
Positive ions, they are formed by losing electrons.
What are anions and how are they formed?
Negative ions, they are formed by gaining electrons.
What are electrostatic forces?
The force of attraction between oppositely charged particles (forces of attraction between all positively and negatively charged objects). These forces hold the oppositely charged ions together, and form an ionic bond between them.
What is an ionic bond?
A strong electrostatic force of attraction between oppositely-charged ions.
What is the charge of an ion when talking about ionic bonds?
The charge on the ion is showing how much electrons are gained or lost to make it a full outer shell. The charge of + (when losing ions) or - (when gaining ions) is added to the element. Eg: Bromide ion= Br1+ as it lost one electron.
What are Ionic compounds and how are they formed?
It is a substance made up of ions of different elements and are formed by the loss and gain of electrons.
How are ionic compounds held together?
They are held together by strong electrostatic forces.
What is an ionic lattice structure?
An arrangement of many ions that are bonded together in a fixed, regular, grid-like pattern.
What do ionic compounds often form and why?
Ionic compounds often form crystals when solid because of their regular lattice structure. The shapes of the crystals are determined by the structure of the lattice.
How do you work out ionic formulae?
Ionic compounds have no overall charge, so the formula of an ionic compound contains the same number of positive charges as negative charges. To work out ionic formulae, you need to use ion formulae.
What are some common positive ions (ion formulae)?
Sodium: Na+
Lithium: Li+
Potassium: K+
Magnesium: Mg2+
Calcium: Ca2+
Aluminium: Al3+
What are some common negative ions (ion formulae)?
Fluoride: F-
Chloride: Cl-
Bromide: Br-
Oxide: O2-
Sulfide: S2-
Phosphide: P3-
How do you work out the ion formula (Na+ and S2-)?
You need to balance the two formulae out. E.g: Sodium Sulfate contains the ions Na+ and S2-. Therefore two Na+ ions are needed to balance the charges on the S2- ion, and so the formula = Na²S.
What are polyatomic ions?
A group of atoms that have a positive or negative charge due to the loss or gain of electrons (e.g. Nitrate = NO3-).
What are some common polyatomic ions (ion formulae)?
Ammonium: NH4+
Nitrate: NO3-
Hydroxide: OH-
Carbonate: CO₃2-
Sulfate: SO⁴2-
Sulfite: SO₃2-
How do you work out ionic formula when polyatomic ions are involved (Ca2+ and NO³-)?
Calcium Nitrate contains the ions Ca2+ and NO³-. Therefore two NO³- ions are needed to balance the charges on the Ca2+ ion, and so the formula = Ca(NO³)².
What do all ionic compounds contain?
All ionic compounds contain ions. It is important to remember that ionic compounds contain ions, not atoms or molecules.
How do electrostatic forces affect boiling points?
The stronger the electrostatic forces between the ions, the more energy is needed to overcome these forces therefore the ionic compound has a higher melting point.
When do ionic compounds conduct electricity?
Ionic compounds conduct electricity when they are molten or dissolved in water. They do not conduct electricity when solid.
What conditions must be met for a substance to conduct electricity?
- The substance must contain charged particles
- The particles of the substance must be free to move
What is an anode?
A positive electrode.
