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!
One way you could measure this is hitting the two metals with a mallet and seeing which one has more of a dent
B. When scientific understanding changes.
Answer:
The most abundant isotope is 1.007 amu.
Explanation:
Given data:
Average atomic mass = 1.008 amu
Mass of first isotope = 1.007 amu
Mass of 2nd isotope = 2.014 amu
Most abundant isotope = ?
Solution:
First of all we will set the fraction for both isotopes
X for the isotopes having mass 2.014 amu
1-x for isotopes having mass 1.007 amu
The average atomic mass is 1.008 amu
we will use the following equation,
2.014x + 1.007 (1-x) = 1.008
2.014x + 1.007 - 1.007 x = 1.008
2.014x - 1.007x = 1.008 - 1.007
1.007 x = 0.001
x= 0.001/ 1.007
x= 0.0009
0.0009 × 100 = 0.09 %
0.09 % is abundance of isotope having mass 2.014 amu because we solve the fraction x.
now we will calculate the abundance of second isotope.
(1-x)
1-0.0009 = 0.9991
0.9991 × 100= 99.91%
