Name ______

Date ______

Class Period ______

Atoms & Their Characteristics

Choose the letter of the definition that best defines the vocabulary word.

_____1. anode_____2. cathode_____3. electrode

_____4. electron_____5. electron cloud_____6. element

_____7. neutron_____8. proton

A. negatively charged subatomic particle located outside the nucleus

B. positively charged subatomic particle

C. positively charged electrode which attracts negatively charged particles

D. piece of metal through which electrical current enters/leaves vacuum tube - may be

either positively or negatively charged

E. subatomic particle located in the nucleus that has no electrical charge

F. substance that exists in its purest form; all atoms being identical

G. random paths traveled by electrons around the nucleus

H. negatively charged electrode which attracts positively charged particles.

Write the name of the scientist next to the contribution(s) for which the scientist is known.

______1. ideas overshadowed by Aristotle

______2. discovered electrons

______3. shared 1903 Nobel Prize in Physics with the Curies.

______4. discovered alpha and beta waves

______5. followed scientific method

______6. identified Helium

______7. Stated that nature and matter are intertwined

______8. proposed the earliest atomic theory

______9. first to observe radioactive decay

______10. responsible for defining atomic weight

______11. proved electrons were negatively charged

______12. named Hydrogen

______13. discovered Uranium could cause a photograph to develop

without chemicals

______14. theory of simple machines

______15. compiled others’ research into a book about Quantum

Theory

______16. theory of motion

______17. proposed 4 part atomic theory

______18. stated atom was a sphere in which both positive and

negative particles are scattered throughout randomly

______19. presented early version of Law of Conservation of Matter

______20. worked on the creation of the atom bomb

______21. developed cathode ray tube eventually used in televisions

and computers

______22. first to use math to explain molecular behavior

______23. responsible for developing chemical symbols for each

element

______24. identified Radium

______25. created first periodic table

______26. carefully collected and recorded data from performed

experiments

______27. discovered x-rays during a failed cathode ray tube

experiment

______28. brought quantum physics into pop culture in the early

1900s

______29. created a model of the structure of atoms that included a

nucleus and multiple shells

______30. tweaked Bohr’s model by suggesting electrons exist in

clouds not shells

______31. discovered Barium could be used as a fission element

______32. theory of elementary particles

______33. proved quarks existed

______34. believed quarks existed in groups of 4

______35. invented a tool to register radioactive emissions

______36. identified the neutron as a subatomic particle with no

electrical charge

______37. classified the actinide group of elements

______38. discovered the auger effect

______39. proved atoms had a nucleus

______40. received the Nobel Prize in conjunction with Otto Frisch