About Chemistry Quiz #840
Chemistry Quiz #840 was the quiz for Tuesday, October 20, 2026: 10 questions: 3 easy, 4 medium and 3 hard. Everyone who played Chemistry Quiz that day got the same quiz, and it stays here to play for 60 days.
The questions of Chemistry Quiz #840
- Which metal is most used in electrical wires?
- What is the chemical formula for water?
- Which substance has the chemical formula H₂O?
- Which substance has the chemical formula CH₄?
- A substance with a pH above 7 is called what?
- Which substance has the chemical formula NaCl?
- What is the chemical formula for nitrogen gas?
- What is formed when an acid reacts with a base?
- Which element gives fireworks a green colour?
- What is the chemical name for washing soda?
The answer options and the answers appear only when you play the quiz, one question at a time.
New to Chemistry Quiz? The rules, tips and common questions are on the Chemistry Quiz page, and Periodic Table Memory Tips for the Quiz goes into strategy.
Other days of Chemistry Quiz
- Chemistry Quiz #843, Oct 23
- Chemistry Quiz #842, Oct 22
- Chemistry Quiz #841, Oct 21
- Chemistry Quiz #839, Oct 19
- Chemistry Quiz #838, Oct 18
- Chemistry Quiz #837, Oct 17
- Today’s quiz, #851
Every day of the last 60 is in the puzzle archive.