Fluorine
F
9
19
Most reactive nonmetal that is never found free in nature.
Member of Group VII, the halogen family; forms 1
ions;
organic compounds containing this element are used as
nonstick cookware and refrigerants; forms compounds used to
prevent tooth decay
Chlorine
Cl
17
35
Halogen used as a bleaching agent, component of common
table salt, used as a disinfectant and water purifier
Bromine
Br
35
80
Halogen, which is a brownish liquid at room temperature, used
in medicines, dyes, and photography
Iodine
I
53
127
Halogen used as a disinfectant, in photography and as a salt
additive that prevents goiter
Neon
Ne
10
20
Inert gas in Group VIII which produces a red glow in lights.
Argon
Ar
18
40
Noble gas used in welding active metals, denser than air
Krypton
Kr
36
84
An inert element which produces a whitish glow in lights..
Xenon
Xe
54
131
First noble gas to form a compound by stripping away
electrons, used in photographic lamps
Radon
Rn
86
222
Radioactive noble gas used in treating cancer, can collect in
some buildings producing a health hazard
Sodium
Na
11
23
Highly reactive alkali metal of Group I that forms 1
+
ions and
reacts violently with water, never found free in nature and
reacts violently with Chlorine of the halogen family to form
common table salt, required in the body for proper
transmission of nerve impulses
Potassium
K
19
39
Highly reactive member of Group I that reacts violently in
water and is required to allow proper transmission of nerve
impulses
Cesium
Cs
55
133
Highly reactive Group I metal that is a liquid at warm room
temperature (28.5
C), silvery white metal used in making
o
photocells
Rubidium
Rb
37
85
Soft lustrous metal with one electron in its outer shell, reacts
violently with moisture, used in spacecraft engines and
photocells
Francium
Fr
87
223
Extremely rare radioactive Group I metal, contains 136
neutrons and only 87 protons
Magnesium
Mg
12
24
Lightweight member of the alkaline Earth metals of Group II,
forms 2
+
ions, reacts slowly with water and rapidly with steam,
used in making lightweight alloys, found in hydroxide
compounds used as antacids
Calcium
Ca
20
40
Alkaline earth metal found commonly in the Earth’s crust, a
limestone used in making cement or concrete, often found in
pipes or boilers as a result of hard water, forms 2
+
ions
Barium
Ba
56
137
Massive Group II element, a radioisotope of which is used as a
radioactive tracer in medicine
Radium
Ra
88
226
Radioactive Group II element used to treat cancer and in
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