Chapter 2: The chemical basis of life Flashcards
what are important elements?
Phosphorus, sulfur, carbon, oxygen, hydrogen and Nitrogen. ( P.S.C.O.H.N)
Compound
Two or more elements in a fixed ratio
Ionic bonds
Occur between metals and non entails. There is a transfer
Covalent bonds
Metals and metals , sharing equally or non-equal
Nonpolar covalent bond
Neutral charge
Polar covalent bond
Has a charge
Hydrogen bonds
Form between molecules not within
Hydrogen bonds traits
-highly electronegative
- water can form hydrogen bonds
- weaker bonds
Cohesion
Same molecule sticking to each other
Adhesion
Molecules sticking to something else
Surface tension
A measure of how difficult it is to break the surface of a liquid.
Water as a
Solid is less dense than a liquid
Water has a
Specific heat capacity
Capillary action
Important to move water, adhesion and cohesion working together
Density and water
Liquid water = hydrogen bonds are constantly breaking and reforming
Ice = hydrogen bonds are stable
Water’s ability to dissolve
Is due to it being polar
Water is not
A universal solvent
When two atoms are equally electronegative they are __
Nonpolar covalent bonds
Water is able to bond with ___
Other polar covalent Lu bonded molecules
evaporative cooling
A substance evaporates, the liquid of the surface.
- humidity hampers cooling by slowing evaporation of water
What is the role of heat in hydrogen bonds?
Heat is absorbed to break bonds and released to form bonds
Base
A substance that reduces H+ ions
Acid
A substance with a high concentration of h+ ions
Buffers
A substance that donates or takes in H+ ions to minimize change
