Unit 2 Review (2.1 - 2.5)

Which of the following is NOT one of Dalton's postulates of atomic theory?

• Atoms are indivisible.

• Atoms of the same element are identical.

• Atoms can be created and destroyed.

• Compounds are formed from the combination of atoms of different elements.

Tags

NGSS.MS-PS1-5

Who are primarily associated with the development of the electron cloud model?

• J.J. Thomson and Ernest Rutherford

• Niels Bohr and Erwin Schrödinger

• Erwin Schrödinger and Werner Heisenberg

• John Dalton and Niels Bohr

How does the electron cloud model differ from the Bohr model?

• The electron cloud model proposes that electrons orbit the nucleus in specific, defined paths.

• The electron cloud model suggests that the location of electrons can only be described probabilistically.

• The electron cloud model states that electrons have no charge.

• The electron cloud model was developed earlier than the Bohr model.

The smallest particle of an element that retains the properties of that element is called a(n):

• Molecule

• Compound

• Atom

• Ion

A combination of two or more substances that are not chemically combined is a(n):

• Molecule

• Compound

• Element

• Mixture

Protons have a(n) __________ charge.

• Positive

• Negative

• Neutral

• Variable

The mass of a proton is approximately:

• 0 amu

• 1 amu

• 12 amu

• 2000 amu

Electrons are located in the __________ of the atom.

• Nucleus

• Electron cloud

• Valence shell

• Orbitals

The mass of an electron is approximately:

• 0 amu

• 1 amu

• 12 amu

• 2000 amu

The central core of an atom is called the:

• Nucleus

• Electron cloud

• Valence shell

• Orbitals

Tags

NGSS.MS-PS1-1