Chemistry Assessment

Identify the scientist who made the following discoveries

a. Atoms contain negative particles called electrons

• Thomson

• Millikan

• Rutherford

• Dalton

Identify the scientist who made the following discoveries

b. The mass of an electron is 9.11x10-28g.

• Thomson

• Millikan

• Chadwick

• Rutheford

• Dalton

Identify the scientist who made the following discoveries

c. Atoms contain neutral particles called neutrons

• Thomson

• Millikan

• Chadwick

• Rutherford

• Dalton

Identify the scientist who made the following discoveries.

d. Atoms contain a dense, positive nucleus

• Thomson

• Millikan

• Chadwick

• Rutherford

• Dalton

Identify the scientist who made the following discoveries

e. Atoms are indivisible and resemble billiard ball.

• Thomson

• Millikan

• Chadwick

• Rutherford

• Dalton

Describe the evolution of the atomic model from the billiard ball model to the electron cloud model.

• Dalton's billiard ball model-sphere of uniform density. Thomson's plum pudding model-negative electrons dispersed in positive atom. Rutherford's nuclear model- dense, positive nucleus surrounded by negative electrons. Bohr's planetary model-electrons move in circular orbits in specific energy levels. Schrodinger's electrons move within orbital not in specific orbits (Chadwick then added neutrons to the nucleus)

• see above

Write the isotope symbol, including atomic number and mass number for

a carbon-14

• 14/6C

• 53/24C

• 63/28Ni

• 92/40Zr

Write the isotope symbol, including atomic number & mass number, for the following isotopes

b. chromium-53

• 14/6C

• 53/24Cr

• 63/24Ni

• 92/40Zr

Write the isotope symbol, including atomic number & mass number for

c. nickel-63

• 14/6 C

• 53/24 Cr

• 63/28 Ni

• 92/40 Zr

Write the isotope symbol, including atomic number & mass number for Zirconium-92

• 14/6 C

• 53/24 Cr

• 63/28 Ni

• 92/40 Zr