Unit 4 Review

Daulton and Democritus

100

Democritus thought that matter was made of tiny particles that could not be divided. True or False

True

200

How can you describe Daulton's model of the atom?

Solid Sphere

300

The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?

Atom

400

According to John Dalton’s observations, when elements combine in a compound:

a. the ratio of there masses is always the same

b. their volumes are always equal

c. each element contributes an equal number of atoms

a. the ratio of there masses is always the same

500

Which of the following is NOT part of John Dalton’s atomic theory?

• All elements are composed of atoms.
• All atoms of the same element have the same mass.
• Atoms contain subatomic particles.
• A compound contains atoms of more than one element.

• Atoms contain subatomic particles.

Thompson and Rutherford

100

Which statement best describes Rutherford’s model of the atom?

• It is like an avocado with the pit representing the nucleus.
• It is like an aquarium with swimming fish representing positive charges.
• It is like a fried egg with the yolk representing the nucleus.
• It is like a huge stadium with a positively charged marble at the center.

• It is like a huge stadium with a positively charged marble at the center.

200

Rutherford’s gold foil experiment provided evidence for which of the following statements?

• Negative and positive charges are spread evenly throughout an atom.
• Alpha particles have a positive charge.
• Gold is not as dense as previously thought.
• There is a dense, positively charged mass in the center of an atom.

• There is a dense, positively charged mass in the center of an atom.

300

J.J. Thomson’s experiments provided evidence that an atom has what?

negative charged particles

400

In an atomic model that includes a nucleus, positive charge is where?

the center of the atom

500

Who provided evidence for the existence of a nucleus in an atom?

Rutherford

Subatomic Particles

100

Which statement about subatomic particles is true?

• Protons, neutrons, and electrons all have about the same mass.
• Unlike protons or neutrons, electrons have no mass.
• Neutrons have no charge and no mass.
• An electron has far less mass than either a proton or neutron.

• An electron has far less mass than either a proton or neutron.

200

Which subatomic particle has a negative charge?

electron

300

Which statement about subatomic particles is NOT true?

• Protons and neutrons have almost the same mass.
• Protons and electrons have opposite charges.
• Unlike protons and electrons, neutrons have no charge.
• Protons and neutrons have the same charge.

• Protons and neutrons have the same charge.

400

The number of protons in one atom of an element is that element’s

a. mass number.                  b. balanced charge.

c. atomic number.                d. isotope.

c. atomic number.

500

To find the number of neutrons in an atom, you would subtract

• mass number from atomic number.
• atomic number from mass number.
• atomic number from electron number.
• isotope number from atomic number.

• atomic number from mass number.

Niels Bohr

100

How was Bohr’s atomic model similar to Rutherford’s model?

Nucleus with electrons around it

200

Where are electrons located in Bohrs model? (What is the place called)

energy levels/orbitals

300

In Niels Bohr’s model of the atom, electrons move

• like balls rolling down a hill.
• like planets orbiting the sun.
• like popcorn in a popcorn popper.
• like beach balls on water waves.

• like planets orbiting the sun.

400

What does the electron cloud model describe about electrons?

• the most likely locations of electrons in atoms

500

What do scientists use to predict the locations of electrons in atoms?

a. probability                       b. algebra

c. geometry                          d. ratios and proportions

a. probability

Elements and Electrons

100

Suppose an atom has a mass number of 35. Which statement is true beyond any doubt?

• The atom has an odd number of neutrons.
• The atomic number is less than 17.
• The atom is not an isotope.
• The number of protons in the nucleus does not equal the number of neutrons.

• The number of protons in the nucleus does not equal the number of neutrons.

200

Which statement is true about oxygen-17 and oxygen-18?

• They do not have the same number of protons.
• Their atoms have an identical mass.
• They are isotopes of oxygen.
• The have the same mass number.

• They are isotopes of oxygen.

300

The glowing of a neon light is caused by electrons emitting energy as they do what?

move from higher to lower energy levels

400

What is the difference between an atom in the ground state and an atom in an excited state?

excited state has more energy

500

What is unique and specific for any given element? (what determines what the element is? Think Lab)

number of protons