A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments.
Process Engineer Salary. A Process Engineer earns an average salary of $70,876 per year. A skill in Simulation is associated with high pay for this job. Most people move on to other jobs if they have more than 20 years' experience in this field. $52,970 - $97,247.
As a petroleum and natural gas engineer, you can expect to earn the highest starting salary among all of the engineers. Starting salaries are around $90,000, and median annual earnings for petroleum engineers are now well above $140,000.s a petroleum and natural gas engineer, you can expect to earn the highest starting salary among all of the engineers. Starting salaries are around $90,000, and median annual earnings for petroleum engineers are now well above $140,000.