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Chapter 2
N/A
50
Chemistry
Undergraduate 1
03/24/2012

Additional Chemistry Flashcards

 


 

Cards

Term
four molecules that make up 96% of living organisms
Definition
hydrogen (H) Carbon (C) Oxygen (O) and Nitrogen (N)
Term
what is matter?
Definition
anything that occupies space and has mass
Term
what is mass?
Definition

the quantity of matter an object has.

mass is not the same as weight

Term
elements
Definition

pure substances that connot be broken down chemically into simpler kinds of matter

each element has a specfic symbol, which consists of one or 2 letters, called its chemical symbol

Term
atoms
Definition

atoms are the simplest unit of an element that retains all the same properties of that element

consists of 3 distinct parts called subatomic particles

the center of the atom is called the nucleus

Term
nucleus
Definition

composed of 2 subatomic particles: protons and neutrons

protons have positive charge

neutrons has neutral charge (no charge)

consists of the mass of the atom

Term
protons
Definition

the number of protons= atomic number

# of protons identifies the element

the positive charge of the proton is balanced by the negative charge of the electron

 electron energy levels: those in the outermost layer have more energy than ones in the inner levels


 

Term
electrons
Definition

surrounding the nucleus is the elcectron cloud

has a negative charge and constanly move around the nucleus

the mass of the electron is so small that it is not even considered when calculating the mass of an atom

 

Term
neutrons
Definition
nuetrons= atomic mass= atomic number
Term
atomic number
Definition
# of protons
Term
atomic weight
Definition
protons + neutrons
Term
valence electrons
Definition

the electrons in the outermost level are called valence electrons

the valence electron will determine how an element will behave chemically

 

Term
compounds
Definition

pure substance made up of two or more elements

Ex: NaCl

Sodium Chloride :)

Term
molecule
Definition
is the simplest part of a substance that retains all of the properties of the substance and can exist in a free state
Term
chemical bonds
Definition

the sharing or transferring of electrons b/w two electrons

(how molecules are made)

2 types of bonding: covelant and ionic

Term
covalent bonding
Definition

formed when two atoms share one or more pairs of electrons

(may have single, double or triple bonds between atoms)

 

Some covalent bonds form polar molecules, which mean that they have a slightly positive and a slightly negative side.

 

Term
polarity
Definition

the oxygen region is slightly negative

hydrogen region is slightly positive

atoms are not arranged in a staright line

Term
ions
Definition

an atom that has lost or gained an electron in it outer shell (very unstable) and now carries a charge.

 

Term
ionic bonding
Definition
formed when electrons are gained or lost
Term
cation
Definition
a postively charged ion
Term
anioin
Definition
negitavly charged ion
Term
hydrogen bonding
Definition

bond between hydrogen atoms already covelantly bonded in a molecule to oppositely charge particles (water molecules)

weak bond that can be easily broken

causes water to cling to itself


Term
chemical reaction
Definition
simply the making and breaking of bonds
Term
chemical equation
Definition

the way a reaction is described in writing

has 3 basic components: reactants, products and arrow

Term
reactants
Definition
the ions or molecules that go into the reaction
Term
products
Definition
the outcome of the reaction
Term
arrow
Definition
describes the direction the reaction is going
Term
3 types of chemical reaction
Definition
sythesis, decomposition, and exchange
Term
synthesis reaction
Definition

building a more complex molecule from many simple ones

Requires energy

Term
decomposition reaction
Definition

a more complex molecule broken down into many smaller ones

releases energy

Term
exchange reaction
Definition

atoms are exchanged between molecules

energy is not required or released.

Term
what factors influence the rate of chemical reactions?
Definition
catalysts, temperature, concentration, and surface of the reactants
Term
catalysts
Definition

is a protein

is destroyed or used up during a reaction

speeds up the reaction

AKA and enzyme

Term
inorganic molecules
Definition

does not contain hydrocarbon groups

often has ionic bonding

Term
solutes
Definition
substances that are being dissolved
Term
solvent
Definition
the liquid that dissolves the substances
Term
solution
Definition
mixture of the solute and the solvent
Term
concentration
Definition

a measurment of the amount of solute dissolved in a fixed amount of solution

 

Term
saturated solution
Definition
a solution in which no more solute can dissolve
Term
hydrophilic
Definition
water loving (usually polar molecules or ions that dissolves or mixes well with water)
Term
hydrophobic
Definition
water hating (usually neutral, non polar molecules such as lipids)
Term
electrolytes
Definition
salts in their ionic form that have the ability to trasmit an electrical charge
Term
dissociation
Definition
the breaking apart of a water molecule into 2 ions of opposite charge (does not equal ionization)
Term
ionize
Definition
ionically bonded substances, that when added to water, it breaks apart into their invidual ions
Term
acids
Definition

1 to 6

if the number of hydrogen ions in a solution is greater than the number of hydroxide ions, the solution is acid

Term
bases
Definition

5 to 14

if the number of hydroxide ions is greater than the number of hydronium ions, the solution is a base

base=alkaline

Term
neutral
Definition

7

blood=7.4

Term
buffers
Definition

chemical substances that neutralize small amounts of acids or bases

helps to maintaim pH of body fluids at normal levels

Term
organic molecules
Definition

conatins hydrocarbon groups whuch are made up of carbon atom carbon atoms covalently bonded to other carbon atoms, hydrogen, oxygen and nitrogen

divided into 4 groups: carbs, protein, lipids, and nucleic acids

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