Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy. If it is in the second energy level, it must have -3.4 eV of energy. An electron in a hydrogen atom cannot have -9 eV, -8 eV or any other value in between. Let's say the electron wants to jump from the first energy level, n = 1, to the second energy level n = 2. The second energy level has higher energy than the first, so to move from n = 1 to n = 2, the electron needs to gain energy.
Computed Tomography (CT) Scan of the Head and Face. Guide. A computed tomography (CT) scan uses X-rays to make pictures of the head and face. During the test, you will lie on a table that is attached to the CT scanner, which is a large doughnut-shaped machine.Your head will be positioned inside the scanner. The CT scanner sends X-rays through the head.hy It Is Done. A CT scan of the head is done to: 1  Find the cause of symptoms, such as confusion, paralysis, numbness, vision problems, vertigo, or headaches, that might mean a brain injury, a brain tumor, a ruptured aneurysm, or bleeding inside the head.
Brain scans. To show abnormalities like a brain tumor, a contrast dye is often used. The dye is injected into a vein in the arm. A brain tumor generally soaks up more dye than normal brain tissue and shows up clearly on the scan; occasionally, a brain tumor does not absorb more dye.T scans. CT scans are a type of X-ray that creates a three-dimensional picture of the head by scanning the head from multiple different angles. A computer combines these images into a detailed, cross-sectional view that shows abnormalities in the brain, or tumors.