Periodic Table - Ho Sun Choi

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Across
  1. 2. / I am the second element from Group 11.
  2. 6. / The city of Johannesburg located in South Africa consists of some of the world's largest deposits of me.
  3. 7. / My name comes from the Greek word lithos meaning 'stone'. I am the 4th element.
  4. 8. / I was the name of a song by David Guetta featuring Sia.
  5. 11. / I am the last element of a group that is only gases.
  6. 12. / My name comes from Greek Mythology: Niobe, daughter of Tantalus.
  7. 13. / I am a transuranic radioactive chemical element with the symbol Pu.
  8. 17. / You have two atoms of me in a water compound.
  9. 18. / My melting point is 321.1 °C.
  10. 19. / My atomic symbol is Sn.
Down
  1. 1. / 75% of the US 5-cent coin called nickel is me.
  2. 3. / I am named after the continent Europe.
  3. 4. / I live in Group 18 and Period 4.
  4. 5. / I am a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust.
  5. 9. / I have the atomic mass of 54.938.
  6. 10. / I am the leader of Group 12, Period 4.
  7. 14. / I am the only liquid in Group 12.
  8. 15. / My symbol is Na.
  9. 16. / I have two electrons in my inner layer, eight in my mid-layer, and 6 in my outer layer.
  10. 17. / I am a gas with the second smallest atomic mass.