Crossword

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Across
  1. 4. Element with atomic number 45
  2. 7. Noble gas used in advertising signs
  3. 9. The lightest metal in the periodic table
  4. 12. Element with the highest ionization enthalpy
  5. 13. The element used as the standard for atomic mass calculations
  6. 15. Least electronegative element
  7. 17. contraction Cause of similar atomic radii of zirconium and hafnium
  8. 18. The only liquid metal at room temperature
  9. 19. Nitrogen family is also known as
  10. 20. Most abundant element in the Earth’s crust
Down
  1. 1. Element essential for chlorophyll formation in plants
  2. 2. The only liquid non-metal at room temperature
  3. 3. Which element has the highest electrical conductivity
  4. 5. Metal extracted from bauxite ore
  5. 6. Highly reactive alkali metal stored under kerosene.
  6. 8. mass Arrangement of elements in Mendeleev’s periodic table was based on
  7. 10. Element showing anomalous electronic configuration 3d⁵4s¹
  8. 11. Name one metalloid other than silicon and germanium
  9. 14. Element with the highest electron affinity
  10. 16. Naturally radioactive noble gas