Across
- 3. First city targeted with an atomic bomb
- 8. Metal with the chemical symbol Fe
- 9. Cold biome with permafrost and limited vegetation
- 10. Mathematics dealing with symbols and equations
- 12. Biological catalyst that speeds up reactions
- 13. 2020 event marking the UK's departure from the EU
- 14. British passenger liner that sank in 1912
- 17. Planet named after a Roman goddess, often called Earth’s twin
- 18. Electrically neutral particle in an atom’s nucleus
- 20. Warm-blooded animal with hair and usually live birth
- 22. Tense political and ideological conflict between the US and USSR
Down
- 1. City divided during the Cold War
- 2. space telescope launched in 1990
- 4. Russian chemist who created the periodic table
- 5. Macromolecule made of amino acids
- 6. Symbolic location of major financial institutions and 1929 crash
- 7. Tendency of an object to resist a change in motion
- 11. Type of plate responsible for earthquakes and mountains
- 15. Highest mountain in Africa
- 16. Number puzzle involving a 9x9 grid
- 18. Organelle that houses DNA in eukaryotic cells
- 19. Single-celled organisms, some beneficial, some harmful
- 21. Famous Austrian composer of “The Magic Flute”