C3 Structure And Bonding Flashcards
3.1 States of matter
The three states of matter are solids, liquids, and gases. The particles in a solid are packed closely together and vibrate around fixed positions. The particles in a liquid are also close together but can slip and slide over each other in random motion. The particles in a gas have, on average, lots of space between them and zoom around randomly. In melting and boiling, energy is transferred from the surroundings to the substance. In freezing and condensing, energy is transferred from the substance to the surroundings. The simple particle model of solids, liquids, and gases is useful but has its limitations because the atoms, molecules, and ions that make up all substances are not solid spheres woth no forces between them.
3.2 Atoms into ions
Elements react together to form compounds by gaining or losing electrons or by sharing electrons. The elements in Group 1 react with the elements in Group 7. As they react, atoms of Group 1 elements can each lose one electron to gain the stable electronic structure of a noble gas. This electron can be given to an atom from Group 7, which then also achieves the stable electronic structure of a noble gas.
3.3 Ionic bonding
Ion ic compounds are held together by strong forces of attraction between their oppositely charged ions. This is called ionic bonding. Besides the elements in Group 1 and Group 7, other elements that can form ionic compounds include those from Group 2 and Group 6.
3.4 Giant ionic structures
It takes a lot of energy to break the many strong ionic bonds, operating in all directions, that hold a giant ionic lattice together. So ionic compounds have high melting points. They are all solids at room temperature. Ionic compounds will conduct electricity when molten or dissolved in water. This is because their ions can then become and can carry charge through the liquid.
