Chemistry Assignment #1
Chapter 4
3. Matter is composed of small particles called atoms that are
indivisible. Atoms of an element are identical in size, mass, and
chemical properties. Atoms of a specific element are different from
atoms of another element. Different atoms combine in simple
whole-number ratios to form compound. In a chemical reaction,
atoms are separated, combined, or rearranged.
4. Dalton explained that atoms are not created or destroyed in
chemical reactions, but only rearranged.
7. A typical atom consists of a central, small, dense nucleus
containing protons and neutrons. The nucleus is surrounded by a
cloud of negatively charged electrons.
9. The deflection toward positively charged plates demonstrated
the negatively charged nature of electrons; the fact that changing
the type of electrode or the type of gas used in the cathode ray tube
did not affect the ray produced led to the conclusion that electrons
are present in all matter.
10. Particle
Electron
Proton
Neutron
Relative Charge
-1
+1
0
Relative Mass
1/1,840
1
1
12. a. radon, 86 protons and 86 electrons
b. magnesium, 12 protons and 12 electrons
13. dysprosium
14. silicon
15. Yes. 9
16. Protons
and Electrons
20
8
26
30
80
Neutrons
26
9
31
34
124
Isotope
calcium-46
oxygen-17
iron-57
zinc-64
mercury-204
Symbol
46
20Ca
17
57
26Fe
64
204
8O
30Zn
80Hg
17. 25 protons, 25 electrons, 30 neutrons. Manganese
18. B –10 10.013 amu x .198 = 1.98 amu
B -11 11.009 amu x .802 = 8.83 amu
Atomic Mass 1.98 amu + 8.83 amu = 10.81 amu
20. by the atomic number
21. the proton
23. Cu –63 62.930 amu x 0.692 = 43.5 amu
Cu -64 64.928 amu x 0.308 = 20.0 amu
Atomic Mass 43.5 amu + 20.0 amu = 63.5 amu
24. Mg –24 23.985 amu x 0.7999 = 19.19 amu
Mg –25 24.986 amu x 0.1000 = 2.497 amu
Mg –26 25.982 amu x 0.1101 = 2.861 amu
Atomic Mass 19.19 amu + 2.497 amu + 2.861 amu = 24.55amu
27. a. nuclear b. chemical
30. Democritus
31.John Dalton
c. neither
d. chemical
32. Democritus’s ideas
Atoms move through empty
space composed of matter.
Different kinds of atoms have
different sizes and shapes.
The movement, size and shape
of different atoms result in
unique properties of matter.
Atoms are indivisible, solid,
homogenous and indestructible.
Observed changes in matter,
result from changes in the
groupings of atoms and not from
changes
in
the
atoms
themselves.
Dalton’s atomic theory
Matter is composed of small
particles called atoms
Atoms of a given element are
identical having the same size,
mass and chemical properties.
Different atoms combine in
simple whole number ratios to
form compounds.
Atoms cannot be created,
destroyed or divided into
smaller particles.
In a chemical reaction, atoms
are separated, rearranged or
combined.
38. Matter is anything that occupies space and has mass. For
example: desk, chair
39. protons and neutrons; positive charge equal to the number of
protons
43. electron < proton = neutron
44. The number of positively charged protons equals the number of
negatively charged electrons.
46. protons and neutrons
48. the electron
58. differ: number of neutrons, masses;
similar: chemical properties, number of protons and electrons
59. They are all equal.
60. mass number = number of protons + number of neutrons
61. number of neutrons = mass number – atomic number
73. Symbol
132
55Cs
59
27Co
163
69Tm
70
30Zn
Electrons
55
27
69
30
Protons
55
27
69
30
Neutrons
77
32
94
40
74. . Symbol
Ga-69
F-23
Ti-48
Ta-181
Electrons
31
9
22
73
Protons
31
9
22
73
Neutrons
38
14
26
108