Answer:
The length of an edge of this unit cell is 407.294 pm
Explanation:
Face centered cubic structure contains 4 atoms in each unit cell and 12 coordination number, occupying about 74% volume of the total cell. Face centered cubic structure is known for efficient use of space for atom packing.
To determine the edge length, a relationship between the radius of the atom and edge length is used.
X = R√8
Where;
X is the length of an edge of this unit cell
R is the radius of the gold atom = 144 pm = 144 X 10⁻¹² m
X = 144 X 10⁻¹²√8
X = 407.294 X 10⁻¹² m
X = 407.294 pm
Therefore, the length of an edge of this unit cell is 407.294 pm
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!
Answer:
38
Explanation:
Symbol: Sr
Atomic mass: 87.62 u
Electrons per shell: 2,8,18,8,2
Atomic number: 38
Electron configuration: [Kr] 5s2
Van der Waals radius: 255 pm
Valence electrons: two
Mass of molecule (g) = Mr of substance over avarogado constant
