Answer:
<u>B. Lithium, because it has two energy levels with one electron in the second level.</u>
Embryonic Skin Cells is the correct answer.
<span>Hope this helps, and Brainliest answer would be appreciated!</span>
When you swallow food, it doesn't just drop down into your stomach. Muscles contract in a wave-like motion to move the food along through the esophagus. This muscle movement is called, peristalsis, or peristaltic waves. These peristaltic waves contract behind the food bolus pushing it along the digestive tract.
I think the answer is non reactive. As the outer shells gets filled ,valency decreases, so reactivity also decreases.
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