CHAPTER 2 Flashcards
Matter
anything that occupies space and has mass
Mass
the amount of matter in an object; remains constant
States of Matter
1) solid 2) liquid 3) gas
Solid
definite volume and shape
Liquid
definite volume, flexible/changing shape
Gas
no definite volume or shape
Energy
the capacity to do work or put matter into motion
States of Energy
1) Kinetic 2) Potential
Kinetic Energy
energy in action/motion
Potential Energy
capable of work, but currently inactive; stored energy; energy of position
Forms of Energy
1) chemical 2) electrical 3) mechanical 4) Radiant or Electromagnetic radiation
Chemical Energy
energy stored IN BONDS of chemical substances
ex: ATP most useful form of chemical energy in living systems
Electrical Energy
energy that results form movement or charged particles
ex: ions moving across cell membranes
Mechanical Energy
energy directly involved in moving matter
ex: legs pedaling a bike
Radiant Energy
or Electromagnetic Radiation.
Energy that travels in waves
ex: x rays, visible light, infrared, radio and ultraviolet waves
Can Energy be created or destroyed?
no, it can be converted from one form to another. conversion is inefficient and lose some energy in the form of heat.
Elements
composed of atoms and has its own unique physical and chemical properties
Physical Properties
observable with the senses and measurement
Chemical Properties
how atoms interact with other atoms
What are the major elements of the human body?
Oxygen- 65%
Carbon- 18.5%
Hydrogen- 9.5%
Nitrogen- 3.2%
Major elements make up what percent of body weight?
96%
Why are trace elements important?
essential parts of enzymes or are required to activate enzymes
What is the structure of an Atom?
it is composed of subatomic particles that differ in mass, charge and location in the atom
What is the mass, charge and location of a Proton?
1 amu, positive charge, and located in the atomic nucleus
what is the mass, charge and location of a Neutron?
1 amu, no charge, and located in the atomic nucleus
what is the mass, charge and location of an Electron?
0 amu, negative charge, and it orbits the nucleus
which subatomic particles account for 99.9% of an atoms mass?
the protons and neutrons. aka the nucleus
which subatomic particals determine the chemical behavior of an atom?
the electrons
Why are atoms electrically neutral?
there are always equal numbers of protons and electrons
What is the atomic NUMBER and where is it written?
the number of protons in the nucleus.
written as the left sub-script
What is the atomic MASS and where is it written?
the sum of protons and neutrons in the nucleus
written as the left post-script
Isotopes
elements that have the same number of protons and electrons but differ in neutrons
Radioisotopes
isotopes of atoms that decay spontaneously into more stable forms (radioactivity). can transform elements into different ones
Molecule
particle composed of 2 or more atoms joined together by chemical bonds; atoms can either be the same or different
What is the difference between molecules of an element and molecules of a compound?
molecules of an element are atoms of the SAME element joined.
molecules of a compound are composed of 2 or more DIFFERENT atoms that are chemically bonded.
Mixture
substance composed of 2 or more components that are physically intermixed; include solutions, colloids and suspensions.
Solvent
Substance present in the greatest amount that dissolves other substances i.e. water
Solute
substance that is dissolved in a solvent, creating a solution
Homogeneous Mixture
identical composition though out
ex: salt water
Heterogeneous Mixture
composition is dissimilar in different areas of the mixture. samples vary in composition
ex: fruit salad jello
What are the different types of mixtures?
1) solution 2) Colloids/Emulsions
3) Suspensions
What are key characteristics of SOLUTION mixtures?
homogeneous can be gas, liquid or solid small particle sizes solvent: water Usually transparent
ex: ocean (salt) water, air (H20)
What are the key characteristics of COLLOID mixtures?
also called EMULSIONS heterogenous exhibit sol-gel transformation medium size particles that do not settle out over time appear milky, almost translucent
ex: butter
What are the key characteristics of SUSPENSION mixtures?
heterogeneous mixture
large particles that settle out over time
ex: sandy water
Mixtures vs. Compounds
compounds: chemical bonding, can be hetero- or homogeneous
mixtures: separation by physical means, can be hetero- or homogeneous
Chemical Bond
energy relationships between the electrons of reacting atoms
Shell
orbits for electrons
Valence Shell
atoms outermost energy level; chemically reactive
Valence Electrons
electrons in the outermost energy level (valence shell); chemically reactive
Which shell has the highest energy level and why?
the outer (valence) shell, becuase it is not as strongly bound to the nucleus, due to the distance
Octet Rule/Rule of Eights
the tendency of atoms to interact in such a way that they have 8 electron in their valence shell.
Chemically Inert Elements
atoms are filled to capacity (contains 8 electrons) therefore they are stable and unreactive
Chemically Reactive Elements
the innermost energy level is not full; tend to gain, lose, or share electrons
What are the different types of chemical bonds
1) ionic
2) covalent: polar and non-polar
3) hydrogen
Ionice Bond
one atom donates one or more valence electrons and another atom picks up/adds one or more valence electrons, resulting in the formation of ions (hence IONIC bond)
Ion
atoms/molecules with a positive or negative charge
Anion
accepts/gains electrons and forms a net NEGATIVE charge
Cations (ca+ions)
give up/lose electrons and form a net POSITIVE charge
How to Ionic bonds form?
the net positive charge on on ion is attracted to the net negative charge on another ion., like magnets.
How do Covalent bonds form?
when certain atoms interact and they share one or more valence electrons to fill their valence shells.
How many electrons do single, double and triple covalent bonds share
1, 2 and 3 electrons
What is the different between POLAR and NON-POLAR covalent bonds?
non-polar are balanced, polar have unequal electron pairing
Polar Covalent Bonds
2 or more poles of charge
one atom is an electron “hog”
the two ends or poles of the molecule differ
Electronegative- attract electons
Electropositive- low electron attracting ability, usually lose electrons
What is an example of a non-polar covalent bond?
CO2: O=C=O ( = meaning covalent bond)
What are the characteristics of a Hydrogen Bond?
too weak to bind atoms
bonds form, break, and re-form
responsible for high surface tension of water
Surface Tension
measurement of how difficult it is to stretch or break the surface of a liquid
Cohesion
intermolecular attraction of like molecules to one another
Adhesion
attraction between dissimilar molecules of surfaces
Chemical Reactions
involve the formation and breaking of bonds between atoms.
involves the rearrangement of atoms to form different molecules
How do reactants and products relate?
Reactants interact to yield the products
What are the types of chemical reactions
1) Synthesis Reaction
2) Decomposition or Degradation Reaction
3) Exchange or Displacement Reaction
4) Oxidation Reduction Reaction
Synthesis Reaction
to make or build something bigger
ex: AB+C+DEF= ABCDEF
Decomposition Reaction
Degradation
break larger things down into smaller things
ex: ABCDEF -> ABC D EF
Exchange Reaction
Displacement
combination of decomposition and synthesis
ex: ABC+DE -decomposition->A+B+C+D+E -synthesis-> ABDE+C
Oxidation Reduction Reaction
one reactant loses electrons (oxidation) and the other reactant gains (reduction) the electrons.
What are some examples of Oxidation-Reduction Reactions
Photosynthesis H2O+CO2–> C6H12O6+O2
Cellular Respiration C6H12O6+6O2 –>6CO2+6H2O+ATP
Denaturation
when temperatures get so high it causes a change in the chemical structure of a substance
Biochemistry
chemistry of living matter; organism possess inorganic and organic components
Inorganic substances vs. organic substances
inorganic- water, salts, acids, bases and electrolytes
organic molecules- proteins, carbs, lipid, nucleic acids
Acids
proton donors (H+) release hydrogen and anions of the same type when dissolved in water high [H+] and low pH
Bases
proton acceptors
release a cation and hydroxide ion when dissolved in water
slippery to the touch
Electrolytes
minerals in your blod and other fluids that carry and electric charge
