Test 2

What is the correct term for item #1

• proton

• neutron

• electron

• isotope

What is the correct term for item #2

• proton

• electron

• neutron

• isotope

What is the correct term for item #3

• proton

• neutron

• electron

• isotope

What list is in the correct order from smallest to largest?

• electrons-atoms-molecules-mixture

• molecules-atoms-electrons-mixture

• mixture-molecules-atoms-electrons

• electrons-mixture-atoms-molecules

J. J.Thomson observed that a cathode ray is diverted by electrically-charged metal plates. The ray was attracted by a positive plate and repelled by a negative plate. What conclusion did Thomson draw from his observations?

• The cathode ray is a high energy form of electromagnetic wave

• The cathode ray consists of small, rapidly moving negatively-charged particles

• The cathode ray is made up of electrically-charged atoms of a gaseous element

• The cathode ray is emitted by the nucleus of a large atom during a nuclear change

This illustration represents Rutherford’s observations from his gold foil experiment. Alpha particles approached the foil at high velocity. As shown, most passed through the foil but some were deflected.

What is one of Rutherford’s conclusions based on these observations?

• Atoms are more massive than previous experiments had indicated.

• The outer part of the atom is negatively charged and deflects the incoming particles.

• The atomic nucleus is dense enough to exert a gravitational effect on the particles.

• The nucleus of the atom has a concentrated positive charge that repels alpha particles.

How many electrons are in the outermost energy level of a neutral carbon atom?

• 2

• 4

• 6

• 8

This Bohr model represents a hydrogen atom.

In this model, what do the dashed circles numbered 1, 2, and 3 represent?

• the locations of the electrons

• the exact path of an electron orbit

• the number and locations of electrons in the atom

• the allowed energy levels of the electron of the atom

In the electron cloud model of the atom, what does the cloud represent?

• the limits of the electron location

• the probability of the electron location

• the average distance between the electron and the nucleus

• the minimum distance between the electron and the nucleus

In his model of the atom, Bohr proposed that electrons move at fixed distances from the nucleus and that the energy of the electron is related to its orbit. What discovery contributed to the development of this atomic model?

• Electrons can flow freely through metals making metals good conductors.

• Elements have characteristic wavelengths of light emission and absorption.

• Noble gas elements are much less reactive than most other elements

• Electrons exhibit properties of both particles and waves.