Topic 2 - Chemical Level of Organization Flashcards
(57 cards)
Matter
Anything that occupies space and has mass
Mass
The actual amount of matter in an object
Weight
A measure of the gravitational pull of earth on an object
Element
Substance that cannot be split into smaller units through ordinary chemical means
Atom
Smallest unit of matter that retain the properties and characteristics of the element
Mass Number
The sum of the masses of all the protons and neutrons in an atom (can vary depending on number of neutrons)
Isotope
Atoms of an element that differ in the number of neutrons they contain
Atomic Weight
Average of the mass numbers of all the isotopes of an element, taking into account their relative abundance in nature
Molecule
Two or more atoms chemically bonded together
Compound
A molecule consisting of two or more different types of elements
Octet Rule
Only 8 electrons from each valence shell can participate in bonding (2 in first shell)
Non-polar covalent bond
Electrons are shared equally
Polar covalent bond
Electrons are more attracted to one atom than the other
Hydrogen bond
Attractive force between the electropositive hydrogen of one molecule and an electronegative atom of another molecule; gives water cohesion and surface tension
Chemical bonds from strongest to weakest
Covalent, ionic, hydrogen
Activation energy
The collision energy needed to break bonds and begin a reaction
Factors that increase the rate of a reaction
- Increasing temperature
- Increasing concentration
- Smaller particle size - move faster
- Catalysts - remain unchanged
Oxidation-reduction (redox) reaction
Electron donor loses electron (oxidized). Electron donor gaining electron is reduced. E.g. Reactions in which food fuels are broken down
Inorganic Compounds
Simple molecules that lack carbon. E.g. H20, acids, bases, and salts
Properties of Water
- Polar Solvent
- Important in chemical reactions of metabolism
- High heat capacity
- High heat of vaporization
- Protective lubricant and cushion
Mixture
combination of elements or compounds that are physically blended together but are not bound by chemical bonds
Homogeneous solution
Solvent and small solute particles are intimately mixed so the solutes do not settle out of the solution (transparent)
Heterogeneous suspension
Solutes are large, refract light, and tend to settle out unless the mixture is continuously resuspended.
Colloid
Large, undissolved particles are evenly distributed and form a cloudy suspension