Answer:
In effusion, a substance escapes through a tiny pinhole, or other hole whereas diffusion is the spreading out of a substance within a dispersing medium.
Effusion and diffusion are similar in terms of rates and speeds.
Explanation:
According to effusion, if there is a small hole in a container, a gas will leak from it. So, in this process a substance escapes through a tiny pinhole, or other hole.
According to diffusion, the two solutions will reach the lowest possible concentration of both, if they are combined and not mixed. So, diffusion is the spreading out of a substance within a dispersing medium.
Effusion and diffusion are similar in terms of rates and speeds.
Answer: Time taken by a sound impulse to travel through an aluminum rod 25 kilometers long is 4.9 seconds.
Solution:
Length of aluminium rod = 25 km = 25000 m (1 km=1000 m)
Time taken by sound to travel through aluminium = 5100 m/s (from the table given)

time taken =
Hence, the correct option is 4.9 seconds.
Answer:
D. Burning a peice of wood
Explanation:
Because when you burn wood a chemical reaction happenes between the flames and the wood making the wood into ashes.
Hope this helps you :)
The fluorine atom has a neutron number of 10 it also have 10 valence electrons