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Chemical Reactions
Reaction types and energy
Motion
Energy Transformation
Animal Trivia
100

Which of the following is not evidence of a chemical reaction?

A. A gas forms
 B. A new colour appears
 C. The substance melts
 D. Heat or light is released

C. The substance melts
→ Melting is a physical change, not a chemical one. 

100

What happens to the rate of reaction if the temperature increases?

Faster due to more energy collisions 


100

Define distance and displacement. 

Distance = total path; displacement = straight-line with direction.

100

What does the law of conservation of energy state? 

That energy cannot be created or destroyed 


100

What colour is a hippopotamus’s milk?

Pink! 


200

Define a chemical reaction in your own words.

Substances change into new ones with different properties.

200

A reaction mixture becomes cold to touch. What type of reaction is this?

Endothermic (absorbs heat) 


200

A car travels 180 km in 3 hours. What’s its speed? 

= 60 km/hr 

Speed = 180 / 3 = 60 km/hr


200

A toy car starts with 20 J potential energy and converts 15 J into kinetic. What’s the efficiency? 

a) Wasted energy = 20 - 15 = 5 J

B) 15 / 20 x 100 = 75% efficient 

200

What ocean creature has three hearts and blue blood?

Octopus 

300

Explain the difference between exothermic and endothermic reactions and give one example of each. 

  • Exothermic: Releases heat energy (e.g. combustion, fireworks).
  • Endothermic: Absorbs heat energy (e.g. photosynthesis, ice pack reaction). 
300

List three ways to increase the rate of a reaction

Increase temperature, surface area, concentration 


300

A cyclist travels 6 km north then 8 km east. What are the distance and displacement? 

a) Distance: 6 + 8 = 14 km
b) Displacement:

Square root of 6^2 + 8^2 

Answer: Distance = 14 km, Displacement = 10 km

300

Write a wasted energy transformation for these devices (torch, fan, toaster, speaker).

Torch: Chemical -> Heat 

Electric fan: Electrical -> Sound 

Toaster: Electrical -> Light, sound 

Speaker: Electrical -> Heat  

300

Which animal has one of the strongest bite forces of any land mammal (around 1800 PSI)?

Hippo 

400

Balance this equation:  
__Na + __Cl₂ → __NaCl

2Na + Cl₂ → 2NaCl

400

A reaction transforms 200 J of chemical energy into 140 J heat + 40 J light. Find the wasted energy

  • Total useful energy: 140 + 40 = 180 J
  • Wasted energy: 200 – 180 = 20 J
400

A runner moves 400 m in 80 s. What is their speed, and how long to run 1 km? 

a) Speed = 400 / 80 = 5 m/s 

Time for 1km = 1000 / 5 = 200 seconds (or 3 min 20 seconds) 

400

Name four types of potential energy and give an example of each.

  1. Gravitational potential – water at the top of a waterfall.
  2. Elastic potential – stretched rubber band.
  3. Chemical potential – food, fuel, batteries.
  4. Nuclear potential – inside atoms (nuclear reactions). 
400

What is the only poisonous mammal in the world?

Platypus