Why are chemical symbols universal?
Couldn’t we just write “water” instead of H₂O?
Non-uniform motion
A cyclist speeds up, slows down, and turns corners. Is this uniform motion?
What’s the difference between atoms and molecules?
Are oxygen and O₂ the same thing?
Distance vs displacement
If you jog 200 m around a circular park and return to the starting point, what’s your distance and displacemen...
Why is ozone O₃ instead of O₂?
Oxygen is O₂, so why does ozone have three atoms?
Average speed
You drive 30 km at 60 km/h and another 30 km at 30 km/h. Is your average speed 45 km/h?
How to find the number of moles in a sample?
Example: How many moles in 36 g of water?
Acceleration basics
A car goes from 0 to 72 km/h in 10 sec. What’s its acceleration?
Why does rusting increase the mass of iron?
Isn’t rust just corroded iron?
What are the main subatomic particles of an atom?
We hear about protons, neutrons, and electrons, but what exactly are they?
Retardation
A bus slows from 20 m/s to 0 in 5 sec. What’s the retardation?
Why is an atom electrically neutral?
If atoms contain charges, why aren’t they charged overall?
Graphical motion
On a velocity-time graph, what does the slope represent?
What is an isotope?
Why is carbon sometimes written as C-12 or C-14?
Free fall velocity
If an apple falls from a tree and hits the ground in 2 sec, how fast is it moving just before impact?
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