Answer:
Mark has a speed of 6 MPS (Miles Per Hour)
Explanation:
It took mark 2 hours to ride his bike to his grandma's house, which was 12 miles away. I divided 2 by 12 and got 6. Remember this: mph = miles away ÷ time.
Answer : The energy released by an electron in a mercury atom to produce a photon of this light must be, 
Explanation : Given,
Wavelength = 
conversion used : 
Formula used :

As, 
So, 
where,
= frequency
h = Planck's constant = 
= wavelength = 
c = speed of light = 
Now put all the given values in the above formula, we get:


Therefore, the energy released by an electron in a mercury atom to produce a photon of this light must be, 
Yes, they are the same. They are equivalent.
Answer:
True
Explanation:
The accuracy level is usually determined by the difference between the experimental and correct value. It is important to note that the smaller the difference between the average experimental value and the correct (true) value, the more accurate it is.
When the difference is large then it means the accuracy level is low and not up to the required standard.
Answer: A. uranium salt
Becquerel made a conclusion that it was the uranium that causes the images found in the photographic plates. Though his theory was disproved during the first time,he continued to develop it. Then, it is through this experiment that Becquerel discovered radioactivity.