Textbook Notes (369,082)
Canada (162,376)
Biology (653)
BIO152H5 (140)
Chapter 2

Chapter 2- Water.docx

3 Pages

Course Code
Fiona Rawle

This preview shows page 1. Sign up to view the full 3 pages of the document.
Chapter 2- Water and Carbon: The Chemical Basis of Life Chemical evolution: Early in earth’s history, simple chemical compounds in the atmosphere and ocean combined to form larger more complex substances. 2.1 Building Blocks of Chemical Evolution H, C, N, O make up 96 percent of all matter found in organisms today. -atomic number: protons. Subscript of each element -isotopes: forms of an element with different numbers of neutrons. -mass number: protons plus neutrons -orbital: electrons move around nuclei in specific regions. 2 electrons. Grouped into electron shells. -valence: number of unpaired electrons in an atom. -Atom is most stable when valence shell is filled. -covalent bonds: share electrons; form molecules. -nonpolar covalent bond: equal sharing of electrons. Symmetrical -polar covalent bonds: asymmetric sharing of electrons. Some atoms hold electrons in covalent bonds much more tightly than do other atoms—electronegativity. Electronegativities: O >> N > C= H Ionic bonds: electrons transferred. Gives resulting atom full shell. Cation- loses electron.Anion- gains -Mass of one mole of any molecule is the same as its molecular weight expressed in grams. Molecular weight is the sum of the mass numbers of all elements in a molecule. -Molarity is the number of moles of the substance present per litre of solution -Water is polar meaning the overall distribution of charge is asymmetrical. -ions and polar molecules are hydrophilic. Uncharged and nonpolar are hydrophobic. -Hydrogen bonding makes it possible for almost any charged or polar molecule to dissolve in water. -Properties of water 1. forms hydrogen bonds 2. solvent 3. cohesion- binding between like molecules. Water stays together because of hydrogen bonds between the molecules. 4. adhesion- Binding between unlike molecules. Water adheres to surfaces that have any polar or charged components. 5. surface tension- any force that depresses
More Less
Unlock Document

Only page 1 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.