They have bilateral symmetry and a rounded shape.
Answer:
16) 6 electrons
17) 6 protons
18) 6 neutrons
19) 4 electrons
20) 6
Explanation:
There are 6 electrons on the rings in total and 6 protons inside the nucleus. If you count the black cir les, there are 6 of them so there are 6 neutrons. Knowing that the inner ring can only hold 2 electrons the most, 6-2= 4. So there are 4 electrons on the outer ring. Knowing that you can get the atomic number based on the number of protons an atom have, the at pool mic number would be 6.
Not a specific genetic sequence, some doctors and scientists believe it could be hereditary and others do not believe it is genetic but instead develops due to psychological and environmental factors. Look up the rat park study.