Structure and Discovery of Atoms

Atomic Structure Review

Format

• Google Form with multiple choice questions

• Chart: atomic number, atomic mass, # of protons, # of neutrons, # of electrons

• Drawing Bohr Model and Lewis Dot diagrams

Topics

• History of atomic structure

• Subatomic particles

• Isotopes

• Ions

• Bohr Model Diagrams

• Lewis Dot Diagrams

History of Atomic Structure

• Democritus - first person to describe atoms

• Dalton - solid sphere / cannonball model

• J.J. Thompson - plum pudding model

• Rutherford - gold foil experiment, nuclear model

• Bohr - planetary model

• Schrodinger - wave-mechanical model, most accurate

Atomic Theory

• All matter is composed of very tiny particles called atoms.

• Atoms are indivisible.

• All atoms of the same element are the same.

• All atoms of different elements are different.

• developed by Dalton

• 
  

Multiple Choice

What Greek philosopher was the first person to propose the idea that matter is made of tiny particles called atoms?

• Democritus

• Dalton

• Thompson

• Rutherford

• Bohr

Multiple Choice

Which of the following is the most accurate model of the atom?

• Solid Sphere / Cannonball Model

• Plum Pudding Model

• Planetary Model

• Wave-mechanical model

Multiple Select

Which conclusions were made based on the gold foil experiment? Check all that apply.

• Electrons are found in orbits around the nucleus.

• Most of the atom is empty space.

• The nucleus is positively charged.

• Electrons have a negative charge.

Multiple Choice

Which particle did J.J. Thompson discover?

• Proton

• Neutron

• Electron

• Nucleus

Multiple Choice

Which scientists proposed the solid sphere / cannonball model of the atom?

• Dalton

• Thompson

• Rutherford

• Bohr

• Schrodinger

Multiple Choice

Which scientists proposed the planetary model of the atom?

• Dalton

• Thompson

• Rutherford

• Bohr

• Schrodinger

Multiple Choice

Which scientists performed the gold foil experiment and proposed the nuclear model of the atom?

• Dalton

• Thompson

• Rutherford

• Bohr

• Schrodinger

Multiple Choice

Which scientist proposed the plum pudding model of the atom?

• Dalton

• Thompson

• Rutherford

• Bohr

• Schrodigner

Subatomic particles

• Protons: positively charged, mass of 1 a.m.u., found in the nucleus

• Neutrons: no charge, mass of 1 a.m.u., found in the nucleus

• Electrons: negatively charged, mass so little we consider it zero, found in the electron cloud outside the nucleus

• 
  

• 
  

Multiple Choice

Which subatomic particle identifies an element?

• Protons

• Neutrons

• Electrons

• Protons and Neutrons

Multiple Select

Which particles have a charge?

• Protons

• Neutrons

• Electrons

Multiple Select

Which particles are found in the nucleus?

• Protons

• Neutrons

• Electrons

Multiple Select

Which particles account for almost all the mass of an atom?

• Protons

• Neutrons

• Electrons

Multiple Choice

Magnesium's atomic number is 12. This means that a magnesium atom has

• 12 protons in its nucleus

• A total of 12 protons and electrons

• 12 neutrons in its nucleus

• A total of 12 neutrons and electrons

Multiple Choice

A potassium atom has an atomic mass of 39. Its atomic number is 19. How many neutrons does the iron atom have?

• 19

• 39

• 20

• 58

Isotopes

• atoms of the same element with different numbers of neutrons and therefore different masses

• 
  

• 
  

Multiple Choice

Two atoms that are different isotopes of the same element have

• a different number of protons but the same number of neutrons

• the same number of protons and the same number of neutrons

• a different number of protons and a different number of neutrons

• the same number of protons but different numbers of neutrons

Ions

• charged atoms formed by an atom gaining or losing electrons

Multiple Choice

A neutral atom becomes a negative ion when

• gains electrons

• gains protons

• loses protons

• loses electrons

Multiple Choice

What is the charge of an atom with 5 protons, 5 neutrons, and 7 electrons?

• 0

• +5

• +2

• -2

Bohr Model Diagrams

show location of electrons in orbits/shells/energy levels

Lewis Dot Diagrams

only show valence electrons