Unit 7 - Understanding the Atom

Who of the following determined that cathode rays were negatively charged within the "Plum Pudding" model?

• Dalton

• Thomson

• Aristotle

• Rutherford

Who of the following found that atoms have a nucleus?

• Rutherford

• Democritus

• Dalton

• Thomson

Who hypothesized the existence of an indivisible piece of matter he called the "atomos"?

• Rutherford

• Thomson

• Democritus

• Dalton

Who of the following hypothesized that an atom was the smallest piece of matter that preserved the properties of the larger piece from which it came, using experimentation?

• Rutherford

• Thomson

• Dalton

• Aristotle

Upon what statement would Democritus and Dalton both agree?

• The atom is indivisible

• The atomic number is the number of protons in the nucleus

• The cathode ray proved the existence of electrons

• The atoms of gold foil showed that they are mostly empty space when an alpha particle is shot through them

What piece of equipment was used in the discovery of the proton?

• cathode ray tube

• gold foil and a detector screen

• scanning, tunneling electron microscope

• particle collider

What two particles would be attracted to each other?

• neutrons and protons

• electrons and electrons

• protons and electrons

• neutrons and electrons

Most of the mass of an atom is located in its

• protons

• electron cloud

• electrons

• nucleus

Which of the following statements best describes how the Bohr model of the atom is different from Rutherford's model of the atom?

• Bohr's model did not distinguish between positive and negative charges

• Bohr's model placed electrons in the nucleus

• Bohr's model had more electrons around the nucleus

• Bohr's model showed electrons at discrete distances from the nucleus

Based upon his experiment, Rutherford concluded that atoms were _________________with _____________in the nucleus

• mainly empty space, dense positively charged particles

• uniform throughout, electrons

• densely populated with subatomic particles, only neutrons

• all empty space, nothing