Lec. 2 - Bonds and Water

Question 1

Explain electronegativity as it relates to electrons and atoms.

Answer 1

Electronegativity is a measure of how desperate an atom is for another electron. Higher electronegativity = more desperate atom.

Question 2

Compare the different types of chemical bonds (covalent, ionic, polar, polar covalent); describe differences and how they affect a molecules interactions.

Answer 2

COVALENT bonds share electrons equally, POLAR COVALENT bonds share electrons unequally, IONIC bonds transfer electrons. Atom that looses electron = cation. Atom that gains electron = anion.

Question 3

Explain radioactivity and half-life, and how Carbon-14 can be used to determine the age of an object.

Answer 3

Radioactivity is the release of energy from the decay of nuclei of atoms and isotopes. Half-life is the amount of time it takes for 1/2 of a radioactive isotope to decay. Carbon-14 is used to determine age because it is unstable and decays, so seeing how decayed C14 is tells us the age.

Question 4

Explain why hydrogen bonds are necessary for life: where they are found, why they are important.

Answer 4

Hydrogen bonds provide many life-sustaining properties of water and stabilize protein and DNA structures. Found between polar molecules.

Question 5

Explain why water is important to life; describe a water molecule and the bonds within and between water molecules.

Answer 5

Water functions as a solvent and enables chemical reactions in many cells. Covalent bonds are within water molecules, hydrogen bonds are between water molecules.