Unit 1, chapter 2 of AP Biology text book, including vocabulary and overal summaries of each section along with diagrams. Perfect for studying for the AP exam and other tests throughout the year.
context of Life august 29
~ nit 1 .
Chapter 2 : Chemical michelle B
matter consists of chemical elements in form and in called compounds
. /
2 pure collaborations
1. matter : that takes up space and has mass
anything
A elements and compounds
1. element : any substance that cannot be broken down to other substance by chemical reactions
any
. compound : substance
2 consisting of 2 or m o re different elements combined in a fixed ratio
cannot broken further
3
. matter be down chemically
emergent
4
. properties : compound has chemical and physical characteristics different from those
of i ts constituent elements
, elements
original
13 The elements of Life
1. essential elements Chemical element for to sur vive , grow and reproduce
:
required an
organism ,
.
2 trace elements : elements indispensable for life but required in
extremely minute amounts
. Evolution
C of Tolerance to toxic elements
to tolerate elements that are tox i to
1
organisms evolved others
1 sunflowers absorb metals from
can
heavy tox i c sol
D.
concept check
1. trace elements are essential ,
but required in minute amounts
.
2 effects of iron deficiency include fatigue and anemia
, as it affects
hemoglobin function
2 2
.
an elements properties depend on struc ture of its atoms
1. atom : smallest unit of matter that retains the properties of an element
A subatomic particles
1. nuetuons : no elec tric charge , mass of nucleus of an a tom
17 x 10-24g
, in
.
2 protons : positive charge ,
mass of 17 x 10-24g
, in nucleus of an a tom
about 1/2 , 000 of
negative charge that more
. electrons :
3 , mass proton or n u c t ro n ,
one or more
nucleus of an atom
atomic nucleus : an atoms dense central core contains protons and nuetrons
.
4 ,
. dalton
5 : measure of mass for atoms & subatomic particles ,
some as the atomic mass unit, amy
.
6 figure 2 .
2
Selections
eprotons
⑮
C) :
> because
-
Evetron
no elec trons
S
Cloud of
negative
charge
3. atomic numbers and atomic mass
# of protons in the nucleus of an atom
unique for each element and is subscript
1 atomic number
,
:
total # of protons and nuetons in an atom's nucleus
2 mass
. number :
. atomic
3 mass : total mass of anatom
, equivalent to the mass in
grams of
I mole of the atom
4
. atomic slightly different mass to electrons
mass is than number due negligible mass
S .
NA =
mass :
# of protons + nuetrons
23 # of nuetrons = mass number-atomic number
NA = 23 - 11
1
# of protons
a # of nuetral atom
tomic : electrons in a
C . Isotopes
form of an element, each ws same of protons but different # of nuetrons
I . isotopes : atomic
2
. radioactive Isotope : unstable isotope, nucleus decays spontaneously , giving off particles and
energy
.
3 atoms of element with different # of nuctions
isotopes are same ,
but
4
. isotopes
radioac tive
decay ,
used in research and medicine
, . The
D levels of electrons
energy
to do work
1 .
energy : capacity
to cause change , especially
t h at matter posseses a result of its location or
arrangement
2
. potential energy : Energy as
. electron
3 shells :
energy level of electrons at a characteristic average distance from
nucleus of an a tom
4
. electrons occupy the lowest energy level available , then more to
higher levels by
absorbing energy
elec tron distribution and chemical
E .
properties
1. Valence electrons : an electron in the outermost elec tron shell
. Valence
2 shell : outer most shell of valence elec trons involved
energy an atom ,
w/ in
Chemical reactions of that atom
. electrons
3 determine atoms chemical behavior
4
. valence electrons are crucial for chemical reactions
5
. full valence shells a re inert ;
incomplete shells are reactive
6
. figure 2 6
.
Si Av
H Be F NE Al
zHe 34
4 a
18 13
14 1g
W W --
..... M
11
?
-
11
-
as - ~
-
:e
-
·
·
-
I & -
- I
& & & --
-- -
&
-
&
--
~ ~
F concept check
~
.
I .
Nitrogen atom has 7 protons ,
7 nuetrons
,
radioactive isotope has 8 muetrons
.
mass #IS 7 + 8 = 15 for radioac tive nitrogen . ISN is chemical symbol
.
2 fluroine has a 2 electric shells , first has I needs I more
electrons , I ,
outer has ,
to fill valence shell
.
3 row :
same # of shells
.
same elec tron
Same column : same # of valence electrons, similar chemical properties
2 3
.
the formation and function of molecules depend on chemical bonding between atoms
1. chemical bonds : attraction between 2 atoms of outer-shell elec trons
, sharing or presence
of opposite charges on the atoms
. bonded atoms gain complete outer elec tron shells
* Covalent Bond
1. covalent bonds : type of
strong chemical bond in which 2 atoms share low more pairs of valence
electrons
9
hydrogen
(2H)
atoms
hydrogenmolecule
-because
no elec trons
S
Cloud of
elec + rons negative
approach
become charge
shared in
each others covalent
Proton in nucleus band
2
. molecule : 2 or more atoms held together by covalent bonds
covalent bond ; 2
3
.Single bonds : a
single sharing of a pair of Valence electrons by atoms
4) double bond : double covalent bond ; sharing of 2 pairs of valence electrons by 2 atoms
.
5 of # of
valence : bonding capacity a given atom
; covalent bonds an atom can form ,
usually
#
equals of unpaired electrons in i ts outermost shell
6
.
electronegativity : attrac tion of a
given atom for the electrons of a covalent bond
. nonpolar
7 covalent bond shared between 2 atoms of similar
: electrons a re equally
electronegativity
9
. polar covalent bond :
between atoms that differ in Shared electrons
electronegativity .
a re pulled closer to more electronegative atom
, making slightly
negative and the other a to m
slightly positive
.
9 bonds can be
nonpolar (equal sharing) or
polar (unequal shar i n
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