| Hafnium |
Symbol:"Hf" Atomic Number:"72" Atomic Mass: 178.49amu. Hafnium is one of the transition elements. Hafnium is often found with zirconium. This silvery metal has been put to use in nuclear reactor control rods and in many alloys.
More Information: Transition Metals |
| Halide Mineral |
This is a mineral that is made of compounds with one or more halogen atoms. Salt (Halite) is considered a halide because it has sodium and chloride in the formula.
More Information: Halogens |
| Halogen |
Halogen is the name of the seventh group of elements. They all have seven electrons in their outer shell. They are also very reactive.
More Information: Halogens |
| Hardness |
Hardness is a measure of how easily you can scratch a substance. Diamonds have a greater hardness than copper sulfate crystals. Copper sulfate is softer than a diamond.
More Information: Solids |
| Hardness Points |
Steel rods used by geologists to test the hardness of minerals and rocks.
More Information: Solids |
| Hassium |
Symbol:"Hs" Atomic Number:"108" Atomic Mass: (265)amu. Hassium is one of the postactinide elements. Scientists have created these in labs and may have found only a few atoms of the element. You will not find these in use anywhere.
More Information: Transition Metals |
| Heat Capacity |
A measure of how much heat is needed to raise the temperature of one gram of anything one degree Celsius.
More Information: Thermodynamics |
| Heat of Fusion |
The amount of energy required to transform a substance from a liquid state to a solid state. The amount of energy is measured in calories and is a measure of how many calories must be removed from the system since solids hold less energy overall than liquids.
More Information: Solids |
| Helium |
Symbol:"He" Atomic Number:"2" Atomic Mass: 4.00amu. Helium is a very non-reactive element. It is the first in the group of noble or inert gases. You can find it in balloons, scuba tanks, lasers, nuclear reactors, and blimps.
More Information: Helium |
| Henry's Law |
Gases are able to be dissolved in solvent just like solids and liquids. Henry's law says that gases that don't react with the solute are able to dissolve an amount relative to the partial pressure of the gas over the solution. So, if you have oxygen above water, some oxygen will dissolve in the water. As you increase the pressure, more gas will be able to dissolve in the water.
More Information: Gases |
| Hexagonal Crystal |
This crystal shape has six sides and no specific length. It looks like an elongated hexagon.
More Information: Solids |
| Holmium |
Symbol:"Ho" Atomic Number:"67" Atomic Mass: 164.93amu. Holmium is one of the elements in the lanthanide series of inner transition elements. It may also be classified as a rare earth element. You can find this magnetic metal in many minerals. It has even been used in some lasers.
More Information: Lanthanide Series |
| Hydrogen |
Symbol:"H" Atomic Number:"1" Atomic Mass: 1.01amu. Hydrogen is the first element in the periodic table. It is very light and the smallest atom. There is more hydrogen in the universe than any other element. On Earth, it is usually found with oxygen in water.
More Information: Hydrogen |
| Hydrogen Bond |
A chemical bond that has hydrogen covalently bonded to an electronegative atom. It happens when oxygen bonds to hydrogen.
More Information: Bonding |
| Hydrolysis Reaction |
A reaction that occurs when water is added to a compound. In the case of a disaccharide, the molecule is broken up into monosaccharides with the addition of water.
More Information: Carbohydrates |
| Hydrophilic |
Something that is attracted to water. The term is also used to describe portions of molecules that dissolve well in polar water molecules. "Hydro" means water. "Philic" means to "like or love."
More Information: Compounds |
| Hydrophilic Interactions |
Interactions between molecules where nonpolar portions of the molecule are attracted to any interaction with polar water molecules. The molecule will align itself so that the hydrophobic portions have the best chance of coming into contact with the other polar molecules.
More Information: Compounds |
| Hydrophobic |
Something that is afraid or repulsed by water. The term is also used to describe portions of molecules that do not dissolve well in polar water molecules. "Hydro" means water. "Phobic" means to be afraid of or dislike.
More Information: Compounds |
| Hydrophobic Interactions |
Interactions between molecules in which nonpolar portions of the molecule tend to avoid interaction with polar water molecules. The molecule will align itself so that the hydrophobic portions have the least chance of coming into contact with the other polar molecules.
More Information: Compounds |
| Hydroxide Mineral |
A mineral that is made up of compounds with a hydroxide group bonded to a metal. Bauxite is a good example of a hydroxide mineral.
More Information: Solids |
| Hydroxyl Group |
This is a side group which is one hydrogen atom bonded to one oxygen atom. The result is a negatively charged ion (OH-).
More Information: Acids and Bases |
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