The atomic theory started with Democritus, who stated that all space was made up of indivisible particles called atoms, though Aristotles refuted that statement by saying that matter didn’t exist, he believed in the four elements: air, fire, water, and earth. Then came Dalton, who revived Democritus’s ideas and proposed the law of multiple proportions, he revived the idea that all space was made of atoms. Soon after, J.J Thompson discovered the electron by using cathode rays. Max Planck developed the quantum theory by stating that electromagnetic radiation could only be emitted in quantized form (later called quanta). Einstein furthered this idea with studies of light. Robert Millikan eventually measured the charge of a single electron. Ernest Rutherford used a gold foil experiment and discovered the nuclei, considering his alpha particles were deflected by some object. Niels Bohr made the atomic model with electrons spinning around an atom’s nucleus, Erwin Schrodinger describes how electrons have wave like properties. James Chadwick then discovers the neutron!
There ya have it!
Lewis had proposed that the valence electrons of any substance were arranged around its atoms in a cubic configuration. Later on, this was modified when it was learned that the electrons actually orbit the nucleus, similar to the planets orbiting the sun. Moreover, it is now deduced that the electrons are found in regions, known as electron clouds, and their specific, discrete location at a given point in time can not be determined.
Explanation:
The balanced chemical equation of the reaction is:
From the balanced chemical equation,
1 mole of propane forms ------ 3 mol. of 
gas.
The molar mass of propane is 44.1 g/mol.
One mole of any gas at STP occupies --- 22.4 L.
Hence, 44 g of propane forms (3x22.4 L=) 67.2 L of CO2 gas at STP.
Answer:
Thus, 67.2 L of CO2 is formed at STP.
Answer:
Random motion in all directions.
Explanation:
It must be understood that the movement of atoms in a molecule is strictly based on the kinetic energy possessed by these particles.
Now, the gaseous state gives the highest level of freedom to these particles and thus they possess their highest kinetic energy in this state.
In gaseous helium, the atoms are expected to have a very high kinetic energy and thus they move in a haphazard or in an irregular manner.
This is principally due to the fact that in the gaseous state, atoms are most less confined and thus they are not restricted to a certain space.
This is in sharp contrast to the movement of atoms in the solid and liquid state. While atoms are mostly confined in the solid state such that they only merely vibrate about a fixed point, their movement in the liquid state is less restricted and they exhibit more freedom. This however is far less than the amount of freedom the gaseous state would avail its own particles.
