How is a hydrogen bond different from a covalent or ionic bond?

looks to me that
hydrogen bonds bond with hydorgen
covalent bonds increase the concentration of hydrogen
and ionic bonds decrease the concentration of hydrogen
i guess about the hydrogen bond. wish i was paying attention in biology

Hydrogen bonds are bonds within the bases (adenine bonds with thymine, guanine bonds with cytosine) and covalent and ionic bonds are bonds by which atoms combine to form molecules and so on...

Covalent bonds involve orbital overlaps and actual electron sharing. Ionic bonds are electrostatic - opposite charges attract. Hydrogen bonds are like ionic bonds in that they are electrostatic, but they are a type of dipole-dipole interaction since hydrogen has a low electro negativity and will have a partial positive charge when bonded to say oxygen or nitrogen.

I'm in 8th...I could try. =)

Ionic bonds are formed between metals and nonmetals. Their electrons are transfered.

Covalent bonds are formed between nonmetals and nonmetals, and have shared electrons.

I haven't heard of a hydrogen bond, so I don't know much about that. I know a lot more about ionic and covalent, but I don't know if you really need that. =/

Sorry I couldn't be of more help!

Covalent bond: bond in which one or more pairs of electrons are shared by two atoms.

Ionic bond: bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other.

A hydrogen bond is a special type of dipole-dipole bond.  Hydrogen bonding differs from other uses of the word "bond" since it is a force of attraction between a hydrogen atom in one molecule and a small atom of high electronegativity in another molecule. That is, it is an intermolecular force, not an intramolecular force as in the common use of the word bond. The typical hydrogen bond is stronger than van der Waals forces, but weaker than covalent, ionic and metallic bonds.

Hope that helps.  Good luck

Cookiemonster's answer is correct, but I thought I would put it at a 9th grade level for you.  Covalent bonds share electrons.  Ionic bonds are weaker because they bond by attraction (positive and negative charges).  Hydrogen bonds are actually a type of ionic bond, they involve hydrogen attracted to either oxygen or nitrogen most often.  Hydrogen bonds are the weakest bonds out there, but still very important.  The entire DNA molecule is held in its twisted helix shape because of many many hydrogen bonds.  Hydrogen bonds are also why water has such a high boiling point.

Think of all electrostatic bonds as different in degree of attraction even though all involve attraction between positive and negative.

Covalent bonds are very powerful. They are in a class by themselves. These go to the heart of an atom attracting areas of full charge. The entire shared negative electron cloud surrounds the two deeply embedded, positive nuclei. Some times the cloud hangs off a bit lopsided or uneven so there are areas left more negative. This molecule can then make either a hydrogen or ionic bond with that charged area.

Ionic and hydrogen bonds are very weak compared to covalent. They both depend on orientation between the two molecules. They have to sit with opposing charges facing each other.
When molecules are frantically dancing about as a gas or liquid this snuggled fit doesn't happen often. They are spinning all different ways so even if they briefly align they bump on out they are spinning about so much. As the temperature drops and the gas or liquid solidifies the snug fit between molecules holds longer until many line up. This gives regions of crystalline structure. +-+-+-+-
The difference between ionic and hydrogen is what carries the localized charges.

Molecules with distinct regions of charge can be positive like cations or negative like anions. Ionic bonds form between two partially charged molecules if they slowly line up plus to minus. They do not merge but stay next to each other. Here it helps to look at the periodic table and see the metals in a column, these are the most common anions. The 2 left columns have the most common cations.

Hydrogen bonds form between hydrogen who is the only atom so willing to donate an electron that it is always essentially positive and molecules that have a negative region. The negative regions are most often OH (hydroxyl group) or NH (amine group). The hydrogen has to sit next to the negative region of the oxygen or nitrogen to fit plus to minus charges. Because these often involve very large molecules the many little pulls holding the two together become very powerful.