Chapter 3 Test: ATOMS! ATOMS! ATOMS!

The law of definite proportions

• Contradicted Dalton’s atomic theory.
• Agrees with Dalton’s atomic theory
• Replaced the law of conservation of mass.
• Assumes that atoms of all elements are identical.

The atomic theory proposed by Dalton has been

• totally discarded.
• accepted unchanged to the present day.
• expanded and modified.
• found to be plagiarized.

In early experiments on electricity and matter, an electrical current was passed through

• a glass tube containing water.
• a glass tube containing liquid oxygen.
• a glass tube containing gas under high pressure.
• a glass tube containing gas under low pressure.

The rays produced in a cathode tube are

• unaffected by a magnetic field.
• found to carry a positive charge.
• deflected away from a negative plate.
• striking the cathode.

In Rutherford's experiments, most of the particles

• bounced back.
• were absorbed by the foil.
• passed through the foil.
• combined with the foil.

Rutherford's experiments led him to conclude that atoms contain massive central regions that

• have a positive charge.
• have a negative charge.
• have no charge.
• have both protons and electrons.

The nucleus of an atom has all the following characteristics except that it

• is positively charged.
• is very dense.
• contains nearly all of the atoms' mass.
• contains nearly all the atom's volume.

The radius of an atom extends to the outer edge of the

• nucleus.
• region occupied by the neutrons.
• region occupied by the electrons.
• positive charges.

Isotopes are atoms of the same element that have different

• principal chemical properties.
• number of electrons.
• numbers of protons.
• masses.

The average atomic mass of an element is the average of the atomic masses of its

• naturally occurring isotopes.
• radioactive isotopes.
• two most abundant isotopes.
• artificial isotopes.