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
~ 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
