Worksheet - Chapter 5A - Atomic Structure
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2010
Atomic Theory Matching - Sec. 1 & 2
1.
This device gave scientists their first
A.
Democritus
image of individual atoms. [Fig 5.3.]
B.
John Dalton
2.
He confirmed the existence of the neutron. C.
J.J. Thomson
3.
He developed the beginnings of the modern D.
James Chadwick
atomic theory in the 1800s.
E.
Ernest Rutherford
4.
He developed an elaborate experiment that F.
Scanning Tunneling
showed that the majority of an atom is empty
Microscope (STM)
space, with most of its mass concentrated in a tiny nucleus.
5.
He first suggested the presence of atoms and named them atomos (“indivisible”).
6.
He used a cathode ray tube to discover electrons.
Sec. 1 - Atoms
John Dalton and Democritus agreed that all elements are composed of _____________
particles called atoms.
Unlike Democritus, Dalton performed ________________ to test and correct his theory.
100 000 000 copper atoms lined up would form a line __ ____ long .[See Fig. 5.2.]
F 10. There are 4 trillion times as many copper atoms in a penny as people on Earth.
Sec. 2 - Atomic Particle Matching
11. Nearly weightless, with a negative (-1) charge
A.
Protons
12. 1840 X the weight of an electron, positive (+1) charge
B.
Neutrons
13. Same mass as a proton, but with no (0) charge
C.
Electrons
14. Negative charge determined by Millikan; have 1/1840th of the mass of a proton;
15. Discovered by J.J. Thomson; deflected towards the + plate in a cathode ray tube.
16. Discovered by Chadwick – found last because of their lack of electrical charge
17. Discovered by Goldstein (going in the opposite direction of cathode rays)
____ 18. Found in the nucleus (nucleons) – they contain nearly all of the atom’s mass
19. Found circling the nucleus in orbital clouds - nearly weightless
20. All atoms except hydrogen have this neutral particle.
____ 21. 1 amu mass
____ 22. 0 amu mass (weightless)
23. 0n1
____
24. 1P1
____ 25. -1e0
26. Atomic number is the number of these in a certain element.
____ 27. Add these two together to find the element’s mass number.
28. A hydrogen nucleus (1H1) is really just one of these (1P1).
A.
Sec. 2 - Atomic Particle Picture Matching
Electron
B.
Neutron
____ 29.
C.
Proton
____ 30.
____ 31.
Sec.3 - Distinguishing Between Atoms
32.
The ___________ number of an element is the number of protons in its nucleus.
33.
Do all Carbon atoms have an atomic number of 6? _______
34.
Can, say, a Nitrogen atom have an atomic number of 6 also? ______
35.
_________ number of an element = the number of protons and neutrons in its nucleus.
36.
Do all Carbon atoms have a mass number of 12? _______
37.
For a neutral atom, the number of _______________ is also equal to the atomic number.
38.
[See Table 5.2] a) Which element’s mass number is equal to its atomic number? ___
b) How many of these elements have equal numbers of protons and neutrons? __
c) How many of these elements have more neutrons than protons? ___
d) How many of these elements have more protons than neutrons? ___
39.
Uranium’s mass number is 238. Its atomic number is 92. How many neutrons
does Uranium-238 contain? ________
40.
Carbon-14 has an atomic number of 6. How many neutrons does it contain? _____
41.
[See Fig. 5.8] Use the atomic symbol at the right to answer these questions:
a)
Which element is this? _______________
b)
What is the mass number? ________
c)
What is the atomic number? ________
d)
Number of protons? _____
e)
197
Au
79
Number of neutrons? _____