Across
- 1. the positively charged in nucleus
- 3. the second shell in the atom
- 4. the region for finding the electrons
- 7. when you see this calculated question=, and you will 呕(ou)
Down
- 2. the shape of s-subshell
- 5. the different number of neutrons and same number of protons.
- 6. the ratio that the isotopes occupy the percentage in the nature.