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.
A pregnancy test detects the hCG (Human Chorionic Gonadotropin) hormone in your urine. The presence of this hormone confirms your pregnancy status. Many times, an hCG test proves to be negative even if you are pregnant. This is because hCG enters the blood stream 8-10 days after fertilization (before a missed period).The detectable levels of hCG in urine occur only 1-2 weeks after missing your period.any times, an hCG test proves to be negative even if you are pregnant. This is because hCG enters the blood stream 8-10 days after fertilization (before a missed period). The detectable levels of hCG in urine occur only 1-2 weeks after missing your period.