6. All elements after which number in the periodic table are radioactive?
- 68
- 27
- 179
- 82
- 42
7. The nucleus of an atom takes up 99.9% of its volume.
- False
- True
8. Radiation is dangerous to living organisms because:
- it pulls DNA along with it due to magnetism.
- it ionizes the elements in DNA
- it bashes massive holes in DNA that tear the genes apart.
- it melts DNA
