<span>Valence is defined as number of electrons that are present in the outermost orbital. Oxygen is in the 16th column of the periodic table and the total number of valance electrons is determined by units place digit of the column position which is 6 for oxygen. The outermost orbital is the high energy level and there are two in that orbit. So the valance is +2.</span>
ANSWER FOR QUESTION 1:
The most common type of E. coli infection that causes illness in people is called E. coli O157, which produces a toxin known as Shiga-toxin. Shiga-toxin producing E. coli is abbreviated as STEC. Symptoms of infection with this germ include watery or bloody diarrhea, fever, abdominal cramps, nausea, and vomiting.
ANSWER FOR QUESTION 2:
Some other germs don’t cause as many illnesses, but when they do, the illnesses are more likely to lead to hospitalization. Those germs include: Anyone can get sick from eating contaminated food. Follow four simple food safety steps —clean, separate, cook, and chill—to lower your chance of food poisoning and to protect yourself and your loved ones.
<span>The san Andreas fault
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Chromatids are only called as chromatids when they are sister chromatids, meaning that when chromosome have two double stranded DNA attached together, each of the double stranded DNA is a sister chromatid, and while the whole thing (the two sister chromatids that are attached together) is called a chromosome.
So after the DNA has been replicated, the chromosome consist of 2 sister chromatids, attached to each other at their centromere.
Overall, sister chromatid is one of the two double stranded DNA in a replicated chromosome, and chromosome is the whole "X" shape that we see. For example, in humans, after the S phase of interphase in the cell cycle, we have 46 chromosomes, with 92 chromatids, since each chromosome is an "X" shape, by having two sister chromatids.
Hope this helps!
1. electrical signals travel toward the heart. 2. signal received by the atrioventricular node. 3.signal by the nodes in the atrium. 4.the atria contracts. 5. signal transferred to the ventricles. 6. the ventricles contract.
