How do you calculate and determine atomic number, mass number, and net charge? Atomic number is the number of protons in an atom. Mass number is the number of neutrons in an atom, and net charge describes how the protons and electrons balance out. Tip: This isn't the place to ask a question because the teacher can't reply.
PCL Tear Symptoms & Diagnosis. 1  Pain. Mild to moderate pain in the knee can cause a limp, knee âgiving outâ, or difficulty walking. 2  Swelling. Within hours of the injury, knee will swell rapidly. 3  Instability. Feeling of a loose knee and not stable when standing or walking.
Symptoms. Symptoms of a severe and sudden (acute) anterior cruciate ligament (ACL) injury include: 1  Feeling or hearing a pop in the knee at the time of injury.2  Sudden instability in the knee. 3  Pain on the outside and back of the knee. 4  Knee swelling within the first few hours of the injury. 5  Limited knee movement because of swelling and/or pain.ther health problems can cause symptoms like those of an ACL injury. They include a bone break or injuries to the knee cushions (menisci) or to other ligaments in the knee. For more information on knee injuries, see: 1  Knee Problems and Injuries.