Chem Unit 3

What is the definition of Atomic model history?(in your own words)

What is an atom?

• stable particles that differ in shape and size

• moving particles that differ in smell and size

• moving particles that differ in shape and size

• stable particles that differ in smell and taste

Who proposed the atomic theory in 1803

• John Green

• Harry Potter

• John Dalton

• Adam Theorio

Answer explanation

• 1803:

• He thought atoms were indivisible(nothing that made up the atom)

• Thought each element had own unique type of atom

• Dalton discovered that matter is composed of atoms.

Who created the plum pudding model and said that electrons(aka subatomic particles) exist?

• Thomson

• Rutherford

• Greyson

• Einstein

Answer explanation

• 1897:

• First to discover electronic

• Discover

• Smallest atom: hydrogen

• Plum pudding model

• Model stood for about a decade till Rutherford’s model of the atom

Rutherford determined what?

• 1. Protons are positively charged particles

• Positive nucleus in the center of atoms

• Atoms are mostly empty space

• Atoms take up a lot of space

Answer explanation

• 1909:

• He sent tiny particles through a gold foil made up of atoms and was shocked to find that there was something big enough to repel the charge; he sent alpha particles and was repelled back by particles with the same charge.

• Results implied that atoms must be made up of mostly empty space.

• failed to explain the stability of electrons in a circular path.

Bohr's model of the atom is also called what?

• Greenery Model

• Illusion model

• Planetery Model

• Rutherford Model

Answer explanation

• 1913:

• Electrons are found at fixed energy levels at fixed distances from the nucleus.

• Path closest to the nucleus has the lowest energy level.

• Electrons are able to jump from one energy level to another but are not found between levels.

• Quantum leap: the amount of energy needed to go from one energy level to another.

• The further away the electrons are from the nucleus the more energy 

• Valence electrons are the electrons found in the outermost orbit.

What does Quantum Leap mean?

•  the amount of food needed to go from one house to another.

•  the amount of energy needed to go from one atom to another.

•  the amount of substance needed to go from one level to another.

•  the amount of energy needed to go from one energy level to another.

Who discovered the Quantum Mechanical model(cloud model of the atom)?

• Werner Karl Heisenberg

• Thompson G. Franklin

• McWilliams ze Hogandaz

• Pablo Neruda

Answer explanation

• 1920

• Werner Karl Heisenberg

• Discovered it's impossible to know with certainty the position and momentum of the electron

• Electrons exist in regions not circles

Who found evidence of neutrons, uncharged, subatomic particles?

• James Chadwick

• Juan Estaban

• Stuart Little

• John Bain

Who was able to determine the charge and the mass of an electron?

• Millikan

• Milkacan

• Daveson

• Davison