Answer:
I believe it is B, not 100% sure though
Explanation:
<span>This is because Helium
has two valence electrons compared to Hydrogen which has only one. Helium has
more energy levels for an electron to jump thus more spectral lines to occur.
The spectral lines relating to each change of energy level would be more
grouped together and hence the greater chance of them falling in the visible
range.</span>
Answer:
acceleration
Explanation:
The rate at which velocity changes is the definition of the physical quantity called acceleration, and it is given by the formula: 
where 
is the time that took to change from the initial velocity 
to the final velocity 
A conducting material conducts or allows electricity to flow, while an insulator does not allow electricity to flow. For example think of a water pipe, if the pipe has a hole water can flow, on the other hand if it is just a solid rod, no water can flow through. I hope this helps.
