Across
- 2. it is a heavy metal that is denser than most common materials
- 7. it is a colorless, dense, odorless noble gas found in Earth's atmosphere in trace amounts
- 10. it is a nonmetal with properties that are intermediate between the elements above and below in the periodic table sulfur and tellurium, and also has similarities to arsenic
- 11. the heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius
- 13. it is a very soft, silvery-white metal in the alkali metal group
- 14. it was identified as a new element in 1781 and first isolated as a metal in 1783
- 16. it belongs to group 14 of the periodic table
- 18. a chemical element with the symbol Hf and atomic number 72
- 19. it is in group 18 of the periodic table and is a noble gas
- 20. it is a post-transition metal that makes up 0.21 parts per million of the Earth's crust
Down
- 1. it is named after Tantalus, a villain from Greek mythology
- 3. it occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal
- 4. it is a chemical element with the symbol Cs and atomic number 55
- 5. it is a soft, ductile, and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife
- 6. it is a silvery metal that characteristically has a faint yellow hue
- 8. it is a chemical element with the symbol Ne and atomic number 10
- 9. it is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table
- 12. it was referred to as eka-caesium
- 15. it is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S₈
- 17. it is a colourless, odourless, tasteless gas that is the most plentiful element in Earth's atmosphere and is a constituent of all living matter