Sodium chloride crystal lattice. The lattice energy of a crystalline solid is usually defined as the energy of formation of the crystal from infinitely-separated ions, molecules, or atoms, and as such is invariably negative.ome older textbooks define lattice energy with the opposite sign, i.e. the energy required to convert the crystal into infinitely separated gaseous ions, atoms, or molecules in vacuum, an endothermic process.
2) The term hacker is used in popular media to describe someone who attempts to break into computer systems. Typically, this kind of hacker would be a proficient programmer or engineer with sufficient technical knowledge to understand the weak points in a security system.
Cracking - Method by which a person who gains unauthorized access to a computer with the intention of causing damage. Hacker - Person who gains authorized/unauthorized access to a computer WITHOUT the intention of causing damage.