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: A repeatedly negative pregnancy test and a missed period mean that you are not pregnant; a negative pregnancy test a week or more after your missed period indicates that your chance of being pregnant is less than 1-2%. A positive pregnancy test usually means that you are pregnant. The timing of a positive pregnancy test depends on implantation. If you are pregnant, a urine pregnancy test is not expected to be positive until 3-4 days after implantation (at the very earliest), which is about 10 days after ovulation/fertilization and 4 days before the next period.