Science Lv1
Everyday science for curious beginners, from the solar system to the human body
All 1,000 questions in this category are free to play.
Sign in to start this quizSample questions
Tap an answer to check yourself. Every answer comes with an explanation.
1. What is the chemical formula for water?
2. How many planets are in our solar system?
3. What gas do plants absorb from the atmosphere for photosynthesis?
4. Which organelle is known as the powerhouse of the cell?
5. What force pulls objects toward the center of the Earth?
All 1,000 questions in this category are free to play.
Difficulty that adapts to you
Every question and every player carries an ELO rating, the same system chess uses. Answer correctly and you face harder questions; miss a few and the quiz eases off. That keeps practice in the productive zone - challenging enough to learn from, never so hard it stops being useful.
Each answer shows an instant explanation of what was right and wrong, so a quiz session doubles as a study session.