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.
It is possible to get a negative pregnancy test result when you are actually pregnant. We reveal how often it occurs and why it can happen. Wrong pregnancy test results do happen, and in fact false negatives are more common than false positives. However, itâs also important to say that this shouldnât give you false hope. A negative pregnancy test is still most likely to mean youâre not pregnant. But if you really believe you are pregnant and have pregnancy symptoms, thereâs a chance you may be right. âIf you think you may be pregnant but the pregnancy test is negative, there may be several reasons,â says our expert, midwife Nikki Khan.