Regents Chemistry Exam Explanations June 2014

Base your answers to questions 66 through 69 on the information below and on your knowledge of chemistry.

A student compares some models or the atom. These models are listed in the table below in order of development from top to bottom.

Models of the Atom

Model	Observation	Conclusion
Dalton model	Matter is conserved during a chemical reaction.	Atoms are hard, indivisible spheres of different sizes.
Thomson model	Cathode rays are deflected by magnetic/electric fields.	Atoms have small, negatively charged particles as part of their internal structure.
Rutherford model	Most alpha particles pass straight through gold foil but a few are deflected.	An atom is mostly empty space with a small, dense, positively charged nucleus.
Bohr model	Unique spectral lines are emitted by excited gaseous elements.	Packets of energy are absorbed or emitted by atoms when an electron changes shells.

66 State the model that first included electrons as subatomic particles.

Answer--> Thomson

67 State one conclusion about the internal structure of the atom that results from the gold foil experiment.

Answer--> either atoms ore mostly empty space

or there is a small, dense, positive nucleus

68 Using the conclusion of the Rutherford model, identify the charged subatomic particle that is located in the nucleus.

Answer--> proton

69. State one way in which the Bohr Model agrees with the Thomson model.

Answer--> they both have electrons