Elements 41-50

Element Information
Atomic Numbers 41 through 50

Go to elements 31-40 Return to periodic table Go to elements 51-60

This page contains basic information about elements with atomic numbers 41 through 50. I have tried to make sure the information given here is correct. However, if you find a mistake, please e-mail me at apurdy@centurytel.net, and I will correct it as soon as possible.

Niobium Click here to return to periodic table

Symbol	Nb	Name	Niobium
Atomic Number	41	Atomic Mass	92.906amu
Melting Point	2468°C	Boiling Point	4927°C
Protons/Electrons	41	Neutrons	52
Classification	Transition Metal	State	Solid
Density	6.49 g/cm³	Period/Group	5 / 5
Electronegativity	^1.6	Atomic Radius	146 pm
# of Isotopes	¹	Color	silvery-white
Energy Levels	⁵	Crystal Structure	cubic

Charles Hatchet first discovered Niobium in 1801, and he named it columbium. It was then rediscovered in 1844 by Heinrich Rose, and he gave it the name of niobium.

Uses - stainless steel, magnets

Molybdenum Click here to return to periodic table

Symbol	Mo	Name	Molybdenum
Atomic Number	42	Atomic Mass	95.94 amu
Melting Point	2610°C	Boiling Point	5560°C
Protons/Electrons	42	Neutrons	54
Classification	Transition Metal	State	Solid
Density	10.22 g/cm³	Period/Group	5 / 6
Electronegativity	^2.24	Atomic Radius	139 pm
# of Isotopes	⁷	Color	silvery-white
Energy Levels	⁵	Crystal Structure	cubic

Molybdenum was discovered in 1778 by Carl William Scheele.

Uses - alloy agent for steel, electrodes, catalysts, tool-steel, aircraft and missle parts

Technetium Click here to return to periodic table

Symbol	Tc	Name	Technetium
Atomic Number	43	Atomic Mass	(99) amu
Melting Point	2172°C	Boiling Point	4877°C
Protons/Electrons	43	Neutrons	56
Classification	Transition Metal	State	Solid
Density	11.5 g/cm³	Period/Group	5 / 7
Electronegativity	^1.9	Atomic Radius	136 pm
# of Isotopes	⁰	Color	silvery-gray
Energy Levels	⁵	Crystal Structure	hexagonal

Technetium was discovered in 1937 by Carlo Perrier.

Uses - medical imaging agents, radioactive tracer

Ruthenium Click here to return to periodic table

Symbol	Ru	Name	Ruthenium
Atomic Number	44	Atomic Mass	101.07 amu
Melting Point	2250°C	Boiling Point	3900°C
Protons/Electrons	44	Neutrons	57
Classification	Transition Metal	State	Solid
Density	12.3 g/cm³	Period/Group	5 / 8
Electronegativity	^2.2	Atomic Radius	134 pm
# of Isotopes	⁷	Color	silvery-white
Energy Levels	⁵	Crystal Structure	hexagonal

Ruthenium was discovered in 1844 by Karl Klaus.

Uses - catalysts, platinum alloys

Rhodium Click here to return to periodic table

Symbol	Rh	Name	Rhodium
Atomic Number	45	Atomic Mass	102.905 amu
Melting Point	1966°C	Boiling Point	3727°C
Protons/Electrons	45	Neutrons	58
Classification	Transition Metal	State	Solid
Density	12.41 g/cm³	Period/Group	5 / 9
Electronegativity	^2.28	Atomic Radius	134 pm
# of Isotopes	¹	Color	silvery-white
Energy Levels	⁵	Crystal Structure	cubic

Rhodium was discoverd in 1803 by William Wollaston.

Uses - catalysts, electrical contacts, optical instruments, jewelry, part of the catalytic convertor system in cars

Palladium Click here to return to periodic table

Symbol	Pd	Name	Palladium
Atomic Number	46	Atomic Mass	106.40 amu
Melting Point	1552°C	Boiling Point	2927°C
Protons/Electrons	46	Neutrons	60
Classification	Transition Metal	State	Solid
Density	11.97 g/cm³	Period/Group	5 / 10
Electronegativity	^2.2	Atomic Radius	137 pm
# of Isotopes	⁶	Color	silvery-white
Energy Levels	⁵	Crystal Structure	cubic

Palladium was discovered in 1803 by William Wollaston.

Uses - catalyst for hydrogenation and dehydrogenation reactions, dental crowns, jewelry, medical instruments, electrical contacts

Silver Click here to return to periodic table

Symbol	Ag	Name	Silver
Atomic Number	47	Atomic Mass	107.868 amu
Melting Point	961.9°C	Boiling Point	2212°C
Protons/Electrons	47	Neutrons	61
Classification	Transition Metal	State	Solid
Density	10.5 g/cm³	Period/Group	5 / 11
Electronegativity	^1.93	Atomic Radius	144 pm
# of Isotopes	²	Color	silver
Energy Levels	⁵	Crystal Structure	cubic

Silver has been known since prehistoric times.

Uses - photography, coins, jewelry, silverware, dental alloys, electrical contacts, mirror production

Cadmium Click here to return to periodic table

Symbol	Cd	Name	Cadmium
Atomic Number	48	Atomic Mass	112.40 amu
Melting Point	321°C	Boiling Point	765°C
Protons/Electrons	48	Neutrons	64
Classification	Metal	State	Solid
Density	8.65 g/cm³	Period/Group	5 / 12
Electronegativity	^1.69	Atomic Radius	151 pm
# of Isotopes	⁸	Color	bluish-white
Energy Levels	⁵	Crystal Structure	hexagonal

Friedrich Strohmeyer discovered cadmium in 1817 in a sample of zinc carbonate, and independently, K.S.L. Hermann and J.C.H. Roloff found cadmium at the same time in a speciment of zinc oxide.

Uses - batteries, yellow pigment (in compound with sulfur), control rods and shields in nuclear reactors, TV tube phosphors

Indium Click here to return to periodic table

Symbol	In	Name	Indium
Atomic Number	49	Atomic Mass	114.818
Melting Point	156.6°C	Boiling Point	2080°C
Protons/Electrons	49	Neutrons	66
Classification	Other Metal	State	Solid
Density	7.31 g/cm³	Period/Group	5 / 13
Electronegativity	^1.78	Atomic Radius	167 pm
# of Isotopes	²	Color	silvery-white
Energy Levels	⁵	Crystal Structure	tetragonal

Indium was discovered in 1863 by Theodor Richter and Ferdinand Reich.

Uses - transistors, photocells, coating of some bearings, solders

Tin Click here to return to periodic table

Symbol	Sn	Name	Tin
Atomic Number	50	Atomic Mass	118.71 amu
Melting Point	231.9°C	Boiling Point	2260°C
Protons/Electrons	50	Neutrons	69
Classification	Other Metal	State	Solid
Density	7.31 g/cm³	Period/Group	5 / 14
Electronegativity	^1.88	Atomic Radius	140.5 pm
# of Isotopes	¹⁰	Color	silvery-white
Energy Levels	⁵	Crystal Structure	tetragonal

Tin was known in prehistoric times.

Uses - solder, pewter, bronze, coating for steel cans ("tin cans") and other metals

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