Electron Configuration and Valence Electrons. The electrons in an atom fill up its atomic orbitals according to the Aufbau Principle; Aufbau, in German, means building up..ach element has a number of valence electrons equal to its group number on the Periodic Table. This table illustrates a number of interesting, and complicating, features of electron configuration. Figure %: The periodicity of valence electrons. First, as electrons become higher in energy, a shift takes place.
I took the pregnancy test early at 2 & 3 weeks pregnant, and it came up negative twice. Yet I could feel something was different about my body, even though I had my cycle it fell short a few days, and was very light. Afterwards, I had breast tenderness, and dizziness.
Despite a negative test result, itâs very possible that you are pregnant, but the hCG levels are too low for a test to accurately detect it. Another cause of false-negative pregnancy test results is erratic or improper testing techniques. Most test sticks need to be saturated in urine to get accurate results. If you do not leave your test strip in the urine long enough, it could give you false negative or false positive pregnancy test results. Check the date on the pregnancy test before purchasing it. Out-of-date tests will not give you results you can trust. Also remember that certain fertility medications and rare medical conditions may affect the results of pregnancy tests, and false negatives could be more common in these situations.