Unit 3 Flashcards
What are atoms composed of?
Protons, neutrons and electrons
What is the atomic mass?
The mass of neutrons and protons
What is an isotrope?
Atoms of the same element but different number of neutrons
What are the two types of ions?
Cations: positively charged, more protons than electrons
Anions: have more electrons than protons, negatively charged
What is oxidation and reduction?
Oxidation: loss of an electron=loss of energy
Reduction: gain of an electron=gain in energy
What is the octet rule? How does it affect the tendency to react?
The tendency of atoms to fill up their valence orbital. The fuller the orbital, the less reactive
What are the two possible chemical bonds?
Covalent: sharing of electrons
Ionic: attraction between oppositely charged ions
What is electronegativity?
An atoms attraction for electrons
What determines if a covalent bond will be polar/non-polar?
The difference in electronegativity
What are chemical reactions influenced by?
-temperature
-concentration of reactants/products
-presence of a catalyst
What are hydrogen bonds?
Weak attraction between the partial negative charge of O in H2O to the partial positive charge of H in another water molecule
Can hydrogen bonds only form between water?
No, it can form with another charged molecule
What is water adhesion and cohesion? What is it caused by?
Cohesion and adhesion: water sticks together because of hydrogen bonding
Caused by the polarity of water
What are the 6 properties of water?
1-high specific heat
2-high heat of vaporization
3-solid water is less dense than liquid water
4-water is a good solvent
5-organizes non-polar molecules
6-forms ions
What is the difference between hydrophobic and hydrophilic
The first fears water and the second loves it
What do we mean when we say that water organizes non-polar molecules
These molecules are hydrophobic and water causes them to aggregate or assume specific shapes
The bigger the H+ concentration
The lower the pH, the stronger the acid
Acid is a proton donor or acceptor?
Donor
What is a buffer?
A chemical that accepts/ releases H+ to keep pH constant. Usually composed of an acid and a base
What is the seventh special trait of water
It can act as a buffer
What are the 6 most common elements?
N CHOPS
-nitrogen
-carbon
-hydrogen
-oxygen
-phosphorus
-sulfur
What are macromolecules
Large molecules constructed from smaller subunits
What is the difference between polymers and monomers
Polymer:multiple subunits linked together
Monomer: one subunit
What do you call the forming and breaking of macromolecules
Dehydration synthesis=formation
Hydrolysis=breaking molecules
