Chapter 2 Notes Flashcards
chemistry
Study of the nature of matter
matter
anything that occupies space and has mass (include solids liquids and gases in our bodies as well as surroundings)
all things are composed of
elements
elements
Basic chemical substances that make up matter
20 elements
needed by living things
which for atoms make up 95% of the human body
carbon, oxygen, hydrogen, nitrogen
atoms
tiny particles which make up elements
nucleus
Central portion, positive
parts of the atom
nucleus, electrons around the nucleus
charge of the atom
neutral
nucleus contains
protons, positively charged particles-neutrons, uncharged particles
where are electrons found
found in a cloud outside the nucleus
characteristics of electrons
very small, have a negative charge
atomic number
equal to the number of protons in its nucleus
atomic weight
average of the relative wait (mass numbers) of all the isotopes of an element, neutrons and protons
bonding of atoms
when atoms combine with each other, they gain or lose electrons, or share electrons with other atoms
electrons arranged in
shelves
first shell
two electrons
Second shell
eight electrons
third shell
eight or 18 electrons
ion
particle that gains or loses electrons
atoms that lose electrons become ______ charged
positively
negatively charged
atom that gains electrons
ions
atom with a positive or negative electric charge
ionic bond
atoms that bond by transferring electrons
covalent bond
Chemical bond created by electron sharing between atoms
hydrogen bond
when a hydrogen atom that is already covalently link to the electronegative atom is attacked by another nitrogen or oxygen atom and a bridge is formed between them
molecule
combination of two or more atoms held together by a chemical bond to form a new particle
compound
when two or more different kinds of atoms bond to form a new substance
molecular formula
represent the number and kinds of atoms in a molecule
h2o
2 atoms h 1 atom o
c6h12o6
6 atoms c 12 atoms h 6 atoms o
synthesis
when reactants combine to form a larger more complex molecule a+b->ab
decomposition
when a molecule is broken down into smaller molecules or its constituent atoms ab-> a+b
exchange
parts of the reactant exchange partners, producing different product molecules
ab+cd=ad+cb
reversible
if chemical bonds are made, they can be broken (all chemical reactions)
a+b ab
electrolytes
substances that release ions in water
acids
electrolyte that releases hydrogen (h+) ions in water
hcl-> h++cl-
bases
electrolytes that release ions that combine with hydrogen ions
naoh->na + + oh
1-6
acid
8-14
base
ph
relative concentration of hydrogen ions in various bodily fluids (concentrated units used to measure)
ph scale
0 to 14
7
neutral. contains equal hydroxyl (oh-) and hydrogen (h+) ions
acidic
contains more hydrogen ions than hydroxyl ions
less than 7
basic
alkaline
contains fewer hydrogen ions than hydroxyl atoms
ph above 7
ph
values of importance
2.0
gastric juices (very acidic)
7.4 blood
almost neutral.
how does stomach not burn up
secrets mucus (base) if not ulcer
what happens if ph of blood gets too low
things passing through dissolved
what happens if ph changes
affects metabolism and homeostasis
inorganic
molecules that lack carbon
why are inorganic molecules called electrolytes
dissolve in water
4 common inorganic substances
water, oxygen, carbon dioxide, inorganic salts
water
most abundant compound in body
makes up 2/3 of the body’s weight
water
water is a major component of
blood layers
how are chemicals transported within the body
water
water absorbs
and transports nutrients
