Giant covalent structures. Such as silicon dioxide, have extremely high melting points and low solubility in all solvents. They are non-volatile and conductivity depends on the availability of electrons in the valence shell (eg graphite). If all electrons are used in bonding they are insulators.ow melting points:- The bonds between molecules are very weak, especially when the molecules are small. It only requires a small quantity of heat energy to create enough molecular vibration to break the molecules attraction for one another and the solid melts.
You may first have back pain when you are 30 to 40 years old. Poor physical fitness. Back pain is more common in people who are not fit. Being overweight. A diet high in calories and fat can make you gain weight. Too much weight can stress the back and cause pain. Heredity. Genes play a role in some causes of back pain, such as certain types of arthritis. Other diseases. Some types of arthritis and cancer can cause back pain. Your job.
Burning back pain causes due to skeletal defect: The shape of the spine affects your posture. The spine was subject to skeletal or bony deformities that could have a negative effect on our posture, leading to the development of back pain.