• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Covalent Bonds

Extracts from this document...


Covalent Bonds Covalent bonds are formed when atoms share electrons, one from each atom in a single bond, to form electron pairs, usually making their outermost shells up to eight electrons by this means. This would make them more stable, less reactive and an electronic structure like a noble gas. They are most frequently formed between pairs of non-metallic elements. Non-metallic elements usually have from four to eight electrons in their outermost shells, the so-called valency electrons, which are used for chemical bonding. In any given "full" shell of eight electrons, the electrons occur in four pairs, but in incomplete shells, the electrons exist singly where possible. Sometimes, atoms of elements form covalent bonds with other atoms of the same element. Thus two chlorine atoms form the chlorine molecule, Cl2, by sharing their unpaired electrons. In the case of oxygen (O2), there are two unpaired valency electrons in each atom, so that two electron-pair bonds are formed between the two atoms to complete their octet of electrons, a double bond. ...read more.


Ionic Bonds Ionic bonds are formed through the electrostatic attraction between two oppositely charged ions. This type of bond normally occurs between metallic and non-metallic elements. Metals typically have few valency electrons, and occur in groups I, II, and III of the periodic table; reactive non-metals typically have more electrons in their outermost shells, and occur in groups IV, V, VI, and VII. An ionic bond occurs when a metal loses all its valency electrons, leaving a positively charged ion with a noble gas structure, and a non-metal gains the number of electrons it requires to give it a noble gas structure, and becomes a negative ion. The ionic bond occurs by means of the attraction between these charged particles, but because there are, of course, millions and millions of them in any given sample, they do not just pair off to make simple "molecules". ...read more.


Every ion is strongly bonded to its neighbours, and the whole is thus held in a rigid lattice with a specific shape. They have high melting and boiling points. This is because the very strong bonding associated with ionic compounds means that much energy is required to break these bonds. They are soluble in water. This is because water is a so-called ionizing solvent, because of its polar nature. The water molecule is capable of attaching itself to both positive and negative ions, water is therefore capable of carrying away the ions into solution (in the form of "hydrated" ions), so that the solid eventually dissolves. Non-polar solvents do not dissolve ionic solids. Compounds containing ionic bonds also conduct electricity when in solution (water) or when molten. This is because both the solution and the molten compound contain ions that can move about when an electric current is passed through. Solid ionic compound cannot conduct electricity as the ions are held in their rigid lattice, and are not free to move. Shayon King ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Classifying Materials section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Classifying Materials essays

  1. Marked by a teacher

    Identifying an Ionic Compound. Objectives: To learn and test for metal ions ...

    5 star(s)

    formed a darker orange precipitate than Fe(II). We can say that the higher the positive charge, the darker the precipitate is. The next test was for ammonium ions NH4+ where sodium hydroxide and heat were applied and ammonia gas was released that turned the litmus paper green.

  2. Our experiment consisted of two samples of water containing unknown substances, and our objective ...

    Wash the conical flask and bung thoroughly or get a new one of each. 9. Repeat from step 3 to 7 but this time with sample B. Explanation for the steps 1. The stand need to be sturdy because the weight of the burette containing the soap solution can

  1. Ionic and covalent bond

    * We need lipids because they are a source of energy which are twice the power of carbohydrates * Lipids are made of monomers of glycerol and fatty acids * Proteins are composed of carbon, hydrogen, oxygen, and nitrogen * They are found in cheese, fish, eggs, milk, and meat

  2. To conjecture the structure and bonding of eight unknown solids by analysis of experimentally ...

    dissolution H No Yes Grey/silver film forms on surface of water and wrinkles upon manipulation by glass rod; water appears blackened due to the suspension of black particles *However an excessive quantity was added and there was a solid remnant Summary of results: D and E were soluble in a non-polar solvent.

  1. The Structure of the Atom.

    Therefore the average mass of all chlorine is : Average mass = (37 x 25/100) + (35 x 75/100) = 35.5 The number 35.5 is the relative atomic mass of chlorine. Relative Atomic Mass : The average relative mass of the atoms of an element, taking into account natural abundance

  2. Metal compounds

    reaction Metal replaces less reactive metals from one of its salts Anhydrous salt = no water of crystallisation Acid = substance produces H ions in aq solution Alkali = a soluble base Endothermic reaction = takes in energy from surroundings therefore appears to cool E.g.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work