radioactivity

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Across
  1. 2. Positively charged radiation emitted from radioactive substances.
  2. 3. Nuclei where the number of protons and neutrons are interchanged are ..... nuclei.
  3. 5. Atoms of different elements having the same number of neutrons.
  4. 6. Atoms of the same element having the same atomic number but different mass numbers.
Down
  1. 1. The spontaneous emission of radiation from an unstable atomic nucleus.
  2. 4. Atoms of different elements having the same mass number but different atomic numbers.