Chemistry for Biology - Ch. 2 Flashcards
Atoms
- smallest particles that retain the properties of an element
- made up of subatomic particles (proton, electron, neutron)
Matter
- anything that occupies space and has mass
- is composed of chemical elements
atomic number
number of protons in an element (note: # of protons equals the # of electrons in an uncharged atom)
mass number
of protons + # of neutrons
isotopes
atoms of an element that differ in mass (different # of neutrons)
ion
charged atom; has lost or gained electrons
Loss = + ion
Gain = - ion
molecule
atoms bonded together to fill their valence shell
ionic bond
attraction between oppositely charged ions; electrons jump from one valence shell to valence shell of another, forming 2 ions
covalent bond
atoms SHARE one or more pairs of valence electrons
hydrogen bond
atom in one polar covalent molecule attracted to oppositely charged atom in another such molecule; water molecules stick to each other
polar molecule
molecule with an unequal charge distribution (slightly negative end and slightly positive end)
What are the 4 properties of water that make Earth “liveable”?
- Cohesion/Surface Tension
- Moderation of Temp
- Expansion Upon Freezing
- Versatility as a Solvent
cohesion
attraction of molecules of the same kind; due to hydrogen bonds between water molecules
Heat is ____ when Hydrogen bonds break
absorbed
Heat is ____ when Hydrogen bonds form
released
solute
substance being dissolved
solvent
dissolving agent of a solution
solution
homogenous mixture of substances
What are cations and anions?
positively charged ion (cation) and negatively charged ion (anion)
If [H+] is greater than amount of [OH-], what is the solution on the pH scale?
Acid (pH < 7)
If [H+] is less than amount of [OH-], what is the solution on the pH scale?
Base (pH > 7)
What does the pH scale being “logarithmic” mean?
There is a tenfold increase/decrease in pH
What are the strongest and weakest bonds?
Strongest: Covalent
Weakest: Hydrogen
Is something is 9 on a pH scale, is it acidic or basic?
Basic
If something is 1 on a pH scale, does that make it acidic or basic?
Acidic
The difference between the mass number and atomic number of an atom is equal to the number of _____
Neutrons
What type of bond is it when Sodium and Chlorine bond to form NaCl?
Ionic bond
When water dissociates, what does it dissociate into?
Hydrogen ions
