WHO AM I ?

1234567
Across
  1. 3. invention of single- wire telegraph system
  2. 5. Chemist known for the periodic law and table.
  3. 6. made significant contributions to the study of light scattering.
  4. 7. developed the laws of motion and universal gravitation.
Down
  1. 1. Theoretical physicist known for the theory of relativity
  2. 2. theory of evolution by natural selection
  3. 4. discovered of polonium and radium.