Download the Atom

Dr. Saidane
Chem. 152
Early Model of the Atom
What is the term that corresponds to each of the following definitions?
1. A negatively charged subatomic particle having a negligible mass.
2. A positively charged subatomic particle having an approximate mass of 1 amu.
3. A neutral subatomic particle having an approximate mass of 1 amu.
4. A region in the center of an atom containing protons and neutrons.
5. A value indicating the number of protons in the nucleus of an atom.
6. A value indicating the number of protons and neutrons in the nucleus of an atom.
7. A symbolic method for expressing the composition of an atomic nucleus.
8. Atoms of the same element that have different number of neutrons.
9. A unit of mass exactly equal to 1/12 the mass of C-12 atom.
10. The average mass of all the naturally occurring isotopes of an element.
11. What are the principles of Dalton’s atomic theory?
12. How did the results of the gold foil experiment lead Rutherford to discover the atomic nucleus?
13. How does J. J. Thompson model (plum pudding) differ from Rutherford’s model?
14. What are the three subatomic particles in the atom? What is the electric charge of each?
Describe the major differences between them in terms of size, mass, and location.
15. What does the atomic number represent? What does the atomic mass represent?
16. Explain why the atomic masses given in the periodic table are not whole numbers?
17. How are isotopes of the same element alike? How are they different?
18. What is the percent abundance of a given isotope?
19. Copper has two isotopes: Copper-63 and copper-65. The relative abundances and atomic
masses are 69.2% (mass = 62.93 amu) and 30.8% (mass = 64.93 amu), respectively. Calculate
the average atomic mass of copper.
20. Complete the following table:
Isotope
Carbon-14
Symbol
14
Atomic
# of
# of
# of
Mass
Number
Protons
Neutrons
Electrons
Number
C
6
Iron-56
23
41
Ca2+
20
47
45
Sc4+
109