1) they have similar chemical properties.
for example fluorine from the 17th column is a non metal so does all the elements of that group.
2)they have same valence electrons in their outermost shell
example
electronic configuration of
hydrogen 1, lithium 2,1, sodium 2,8,1 and so on.
3) have same valency.
Answer: the relative differences in arrival times of the S and P seismic waves at several recording stations tell scientists about the different speeds those waves were traveling at, which in turn gives information about the density of the material the layer is made of, and how thick the layer is in several directions.
Explanation:Earth's layers
Answer:
The BRCA gene is a tumor-suppressor gene found in the breast; to be more specific, it produces proteins that suppress cancerous activities/abnormal growth in the body. A mutation in a BRCA gene would allow these abnormal growth activities to go unchecked and thus increase the rate of mitosis. Cell cycle checkpoints would significantly be worse at their jobs of checking and correcting for errors during the cell cycle. Tumors would result as well, as cancerous growth continues, and the tumor can become metastatic.