Final answer:
Graphite and diamond are both forms of carbon; graphite is soft and composed of hexagonal layers, making it good for pencil lead, while diamond is extremely hard due to strong bonding between carbon atoms in all directions. Graphite is stable under normal conditions, diamond is not, but it doesn't readily convert to graphite because the process is very slow.
Step-by-step explanation:
Graphite and diamond are both allotropes of carbon, meaning they are made of the same element but with different structural forms. The structure of graphite consists of layers of carbon atoms arranged in a hexagonal pattern. These layers are held together by weak van der Waals forces, allowing them to slide over each other, which is why graphite is soft and often used in pencil lead. On the other hand, diamond has a three-dimensional structure with each carbon atom strongly bonded to four other carbon atoms, creating a rigid and extremely hard material. These differences in structure also result in contrasting physical properties such as hardness, electrical conductivity, and thermal conductivity.
The graphite surface shows that the distance between the centers of adjacent carbon atoms is approximately 1.4 x 10-10 meters. The stability of graphite and diamond varies based on environmental conditions. Under ambient atmospheric pressure, graphite is the stable form of carbon, whereas diamond, forming at high pressures, is thermodynamically unstable but kinetically stable at room temperature. This means that while diamond would theoretically transform to graphite over time, this process, known as graphitization, occurs extremely slowly at normal conditions.