CHEMISTRY 1

The electrical charges in an atom are located.

• in the nucleus

• in the proton and neutron.

• in the proton and electron

• in the proton, neutron, and electron

Rutherford's alpha scattering experiment indicated that.

• the nucleus of an atom occupies most of an atom's center

• positive charges are dispersed throughout the atom

• positive charges are concentrated in a very small core at the atom's

  center

• protons and neutrons are located in the nucleus

Dalton's atomic theory did not include the postulate that______

• matter is made up of small particles called atoms

• atoms contain electron, proton, and neutron

• atoms are indivisible particles

• atoms enter into a chemical reaction

Which of the following is Rutherford's explanation on why alpha particles passed through the gold foil?

• An atom contains negatively-charged particles

• There must be an empty space in the atom.

• There are very thin portions in the atom.

• There must be some repulsive forces in the atom

An atom is electrically neutral because

• the number of electrons is equal to the number of protons

• the nuclear charge is equal to the number of neutrons

• the nuclear charge is equal to the number of electrons

• the number of neutrons is equal to the number of protons

Which is true for the atomic structure?

• The neutrons and electrons have the same mass.

• The neutrons and protons have opposite charges.

• In the nucleus are the protons, electrons and the neutrons.

• The protons and electrons are equal in number but have opposite

  charges.

Which of the following experiments determined the charge of an electron?

• oil-drop experiment

• gold-foil experiment

• cathode ray tube experiment

• canal rays experiment

Who proposed the atomic theory in the 18th century?

• Antoine Lavoisier

• John Dalton

• Pierre Gassendi

• Robert Boyle

Which of the following is NOT a postulate in Bohr's theory?

• An electron moves around the nucleus.

• An electron moves in an angular momentum.

• Each stationary state in an orbital is associated with a certain energy

• Electrons emit and absorb energy in a stationary state

An atom is

• a tiny indivisible particle the smallest piece of matter

• the smallest piece of matter

• the smallest particle of an element that retains the chemical identity

  of the element that retains the chemical identity of the element

• an artificially assembled unit that contains proton and neutron