Aluminum has an atomic number of 13, so it has 13 protons. In its natural state, it does not have a charge, so it has an equal amount of electrons, 13. The atomic mass of aluminum is approximately 27. Since protons and neutrons make up that mass, and each of the particles are around 1 atomic mass unit, if there are 13 protons, then there are 27-13 neutrons, or 14 neutrons. So the first answer choice is correct.
Answer:
Explanation:
Plate separation, d = 1.76 cm = 0.0176 m
Area of plates, A = 25 cm^2 = 0.0025 m^2
V = 255 V
(a) Capacitance of capacitor
C = 1.258 x 10^-12 F
charge is same before and after immersion as the battery is disconnected
q = C V
q = 1.258 x 10^-12 x 255 = 3.2 x 10^-10 C
(b)
Capacitance before, C = 1.258 x 10^-12 C
capacitance after, C' = k x C = 80 x 1.258 x 10^-12 = 100.64 x 10^-12 C
Where, k is the dielectric constant of water = 80
Potential difference after immersion, V' = V / k = 255 / 80 = 3.1875 V
(c) initial energy,
Final energy
Question
Rutherford tracked the motion of tiny, positively charged particles shot through a thin sheet of gold foil. Some particles travelled in a straight line and some were deflected at different angles.
Which statement best describes what Rutherford concluded from the motion of the particles?
A) Some particles travelled through empty spaces between atoms and some particles were deflected by electrons.
B) Some particles travelled through empty parts of the atom and some particles were deflected by electrons.
C) Some particles travelled through empty spaces between atoms and some particles were deflected by small areas of high-density positive charge in atoms.
D) Some particles travelled through empty parts of the atom and some particles were deflected by small areas of high-density positive charge in atoms.
Answer:
The right answer is C)
Explanation:
In the experiment described above, a piece of gold foil was hit with alpha particles, which have a positive charge. Alpha particles <em>α</em> were used because, if the nucleus was positive, then it would deflect the positive particles. The principles of physics posit that electric charges of the same orientation repel.
So most as expected some of the alpha particles went right through meaning that the gold atoms comprised mostly empty space except the areas that were with a dense population of positive charges. This area became known as the "nucleus".
Due to the presence of the positive charges in the nucleus, some particles had their paths bent at large angles others were deflected backwards.
Cheers!
Answer:
1. 200 metres West
2. Dividing distance by time
3. Speed was unchanged
4. 1800 metres
5. 15 seconds
Explanation:
Running 500 metres West puts you 500 Metres west from the start. Then running 300 metres east puts you 200metres from where you started.
Since displacement is the distance you are from your original position 200 Metres West is the answer
2. Distance = Speed x Time
Rearrange that to get Speed = Distance / Time
3. Acceleration is when the rate of increase or decrease of speed or the direction is changing. When the speed or sirection dont change acceleration is 0
4. Distance = Speed x Time
60 x 30 = 1800 metres
5. Time = Distance / Speed
300 / 20 = 15 seconds
