A) because it is an element.
Explanation: usually when they say pure substance they mean pure element.
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Explanation:
light travel slower in daimond
Answer:
Final speed of the rocket, 
Explanation:
It is given that,
Impulse delivered by an engine, J = 3.5 kg-m/s
Mass of the rocket, m = 120 g = 0.12 kg
To find,
The final speed of the rocket
Solution,
We know that the impulse is equal to the product of mass and velocity o it is equivalent to the change in momentum of an object.




So, the final speed of the rocket once the engine has fired is 29.16 m/s.
Answer:
Most earthquakes and volcanoes occur because of the movement of the plates, especially as plates interact at their edges or boundaries.
Explanation: