The first model of the atom was developed by JJ Thomson in 1904, who thought that atoms were composed purely of negatively charged electrons. This model was known as the 'plum pudding' model.
This theory was then disproved by Ernest Rutherford and the gold foil experiment in 1911, where Rutherford shot alpha particles at gold foil, and noticed that some went through and some bounced back, implying the existence of a positive nucleus.
In 1913, Niels Bohr proposed a model of the atom where the electrons were contained within quantized shells that orbited the nucleus. This was because it was impossible for the cloud of negative electrons proposed by Rutherford to exist, as the negative electrons would be drawn to the positive nucleus, and the atom would collapse in on itself.
In 1926, the Austrian physicist Erwin Schrödinger created a quantum mechanical model of the atom by combining the equations for the behavior of waves with the de Broglie equation to generate a mathematical model for the distribution of electrons in an atom.
However the model used today is closest to the Bohr model of the atom, using the quantized shells to contain the electrons.
For more info:
http://chemistry.about.com/od/chemistryglossary/a/debroglieeqdef.htm
speed of the car is given on the road
reaction time is given as
now we can find the distance that it will move during this reaction time
now the deceleration of the car is 10 m/s^2
so the distance that it will move before stop is given by
so the total distance that it require to stop is given as
while the deer is standing at distance 38 m
so the car will stop 2.8 m before the position of deer
Answer:
Respect the client’s decision
Explanation:
just took the test
Answer:
Clouds form when below the dew point
Answer:
6 V
Explanation:
We can solve the problem by using Ohm's law:
where
V is the voltage in the circuit
R is the resistance
I is the current
In this problem, we know the current, 
, and the resistance, 
, therefore we can find the voltage in the circuit:
