A&P chapter 2

anything that has weight and takes up space. Exists in 3 forms (solid, liquid, gas)

Substances that cannot be split into simpler substances by ordinary chemical means. 

smallest complete unit of an element.  Vary in size, weight, and how they interact with other atoms.  composed of subatomic particles including protons neutrons and electrons. 

Number of protons in the nucleus.  Also the number of electrons.

the average mass of all its naturall accuring isotopes and relects the relative abundance of isotopes with different mass numbers.  

# of neutrons is different than # of protons.  # Protons is always stable.

two or more atoms that form a chemical bond.

atoms of different elements that have formed a bond.

an atom that has a positive or negativ charge due to having enqual numbers of protons and electrons.

atoms that gain an electron become negatively charged ions

atoms that lose an electron become positively charged ions.

outermost shell around the nucleus.

one of 3 electrolytes.  release H+ in water.  proton donors.  

 1 of 3 electrolytes. realease ions that bind to H+ in water (OH-) proton acceptor.  

one of 3 electrolytes. formed when acid and base race and produce water.  when dissolved in water they produce anions and cations but no H or OH.  

a substance that accelerates chemecal reactions; organic catalyst, usually a protein. 

attraction of a positively charged atom and a negatively charged atom 

sharing of electron pairs. formed by the atoms of molecules sharing one, two, or three pairs of the valence electrons.  common, and the strongest chemical bonds in the body.  

atoms unequally sharing electrons

atoms equally sharing electron pairs. 

weak bonds formed between Hydrogen and another atom. found in water, DNA double helix.  

requires that energy be added to form a bond

the bond being broken has more energy than the one formed so that extra energy is released, usually as heat. 

a substance called the solvent dissolves another subsrance call the solute and makes a solution. 

suspended material may mix with the liquid or suspending medium for some time, but it will eventually settle out.  heterogeneous mixtures.  blood, tomato juice. 

homogeneous mixtures containing intermediate particle size.  milk, fog. 

number of electrons (-) = number of protons (+)

the 12 is the atomic mass (protons + neutrons) 6 is the atomic number (number of protons) and C is the name of the  element. (Carbon)

• Ionic bonds are the attraction of + charged atoms and - charged atoms.  covalent bonds are teh sharing of electrons.
• sodium loses and electron to become Na+ and chloride gains an electron to become Cl- = NaCl table salt.  Oxygen has 8 electrons, 6 in second shell.  Two O molecules share 1 pair of electrons to have 8 in outer shell.   

a hydrogen forms when a hydrogen atam with a partial positive charge attracts the partical negative charge of a enighboring electronegative atom, most often larger oxygen or nitrogen atoms.  Hydrogen bonds are weak.  Cannot bind atoms into molecules however they do establish important links between molecules and between different parts of large moleculs such a a protein and nulceic acid.  

exccellent solvent and suspending medium, participates in hydrolysis and dehydration synthesis reactions, serves as a lubricant.  Water molecules are cohesive (behcause of hydrogen bonds) which causes a high surface tension.  water also has a high capacity for absorbing heat and a high heat of vaporiztion. 

the chemical compounds that can convert strong acids or bases in weak ones. 

always contain carbon, usually contain hydrogen, and always have covalent bonds.  Most are large molecules and many are made up of long chains of carbon atoms.  

small organic molecules joined together through dehydration reactions. 

large molecule formed by the vocalent bonding of many identical or similar small building-block molecules. 

small building-block molecules.