Covalent bonds are formed when two atoms are able to <em>share</em> electrons.
Iroinic bonds are form when two atoms are <em> </em> electrons from each other to complete the bond. This results in a pair of ions.
<u>Covalent bonds:</u>
- Have a definite shape.
- Have a low melting point.
- At room temperature they are in a liquid or gas.
- They occur between two non-metals.
<u>Ionic bonds:</u>
- Have no definite shape.
- Have a high melting point.
- At room temperature they are solid.
- They occur between a metal and a nonmetal.
A ) Would be the correct answer!
-Hope this helps you:))
<span>vaccine
The wording given is pretty much the exact definition of a vaccine. The key to how a vaccine works is that it provides to the immune system, samples of the surface proteins of the infectious materials. With those samples available, the immune system is able to produce antibodies that react to those proteins.</span>