To know the density you also need to know the volume of the rock.
Answer:Empty gas cylinders are dangerous because the can explode and cause hazards and empty gas cylinders with open valves can breath,this can cause explosion.
Explanation:
C. A magnet causing a metal object to move
Answer:
b) has leaves that are 8 -10 cm long
Answer:
3.5 yrs
Explanation:
If a sample has decayed to 25%, this means 2 half-lives have passed. We are given this is equal to 7 yrs, and it follows that one half life is 3.5 yrs.
