Chapter 6 - Physical World

The primary purpose of a scientific model is . . .

• to show how complex a theory is.
• to make a complex idea more understandable.
• to make a miniature of the real thing.
• to provide something to show students in a science classroom.

The person who first used the word atom to describe the fundamental particles of matter was .

• the Irish chemist Robert Boyle.
• the English schoolmaster John Dalton.
• the English physicist J. J. Thomson.
• the Greek philosopher Democritus.

Which of the following concepts was first proposed by John Dalton?

• Electrons are arranged in energy levels around the nucleus.
• Each element has its own unique atom.
• The atom consists of mostly space with a tiny dense nucleus.
• The atom can be subdivided into smaller parts.

J. J. Thomson made which of the following contributions to the development of the atomic model?

• Atoms contain negatively charged particles called electrons.
• Atoms contain positively charged particles called protons.
• Atoms contain a tiny dense nucleus.
• Atoms are surrounded by a cloud of electrons in a specific arrangement.

Which of the following ideas was not part of Rutherford's nuclear model?

• An atom consists mostly of open space.
• Atoms contain a tiny dense nucleus.
• Atoms are surrounded by a cloud of electrons in a specific arrangement.
• Atoms contain tiny positively charged particles called protons.

Niels Bohr demonstrated that the colored emissions of incandescent light originate with ...

• the number of protons in the nucleus.
• the emission of alpha particles.
• the arrangement of electrons around the atom.
• the change of energy of the neutrons in the nucleus.

The heaviest or most massive part of an atom is the . . .

• gamma ray.
• neutron.
• proton.
• Electron

The atomic mass unit is based on the mass of the element.

• carbon.
• hydrogen.
• oxygen.
• gold.

The atomic number of an element refers to ..

• the number of protons and neutrons in the nucleus.
• the number of isotopes the element has.
• the number of electrons an ion has.
• the number of protons in the nucleus.

Mass number is required to determine . .

• the charge on an ion.
• the number of protons in the nucleus.
• the isotope of an element.
• the atomic mass of an element.