Chapter 2 Flashcards
(85 cards)
1
Q
what are the 3 components of an atom
A
protons, electrons, neutrons
2
Q
charge of protons
A
(+)
3
Q
charge of electron
A
(-)
4
Q
charge of neutron
A
neutral
5
Q
where are protons and neutrons located in an atom
A
the nucleus
6
Q
where are electrons located in an atom
A
electron cloud or around the electron
7
Q
most of the mass in the atom are contributed primarly by
A
neutrons and protons
8
Q
how much mass does an electron have compared to neutron and protons
A
very small compared to protons and neutrons, contribute and occupy most of the volume of the atom
9
Q
What do the chemical properties of elements and molecules largely depend on?
A
electrons in atoms
10
Q
chemical change
A
changes composition/ structure
magnesium burns in air –> magnesium oxide
11
Q
what is atomic #
A
number of protons in the nucleus of an element
12
Q
do all atoms of the same element have diff # of protons?
A
no all atoms of the same element have the same # of protons
13
Q
how (and with what symbol) is the atomic number indicated
A
by the symbol Z
14
Q
if thr atomic number is 29 how many protons does the atom have
A
29 protons
15
Q
how is the atomic mass unit symbolized
A
u
16
Q
mass of proton
A
1.6272623 x 10^24g
17
Q
atomic mass of proton
A
1.007 amu
18
Q
relative atomic mass for electron
A
<1
0.0005
19
Q
atoms are neutral what does this mean for neutrons
A
of protons = # of neutrons
mass= p+ n
20
Q
what is the radius of an atom
A
30 to 300 pm
21
Q
radius of nucleus
A
~0.001 pm (5 orders of magnitude
smaller than atom)
The atom is mostly
empty space
22
Q
empty space?
A
what the atoms composition is mostly
23
Q
isotape
A
different # of neutrons
24
Q
the mass of one c-12 atom
A
12 u
slide 9 look at
25
C has how many proton and neutron
6 p , 6 n
| has a mass # of 12
26
C-13 has a mass # of 13 u so what does that mean for its proton and neutrons
6 protons and 7 neutrons
27
the atomic mass of fluorine is 19, and its proton number is 9, so what is its neutron #?
10
## Footnote
for a neutral number the number of Electrons have to be the same not neutrons
28
what does the existence of isotopes prove
all atoms of an element are not exactly the same
## Footnote
( #) of protons always has to remain the same but neutron # can vary
29
a^
X
z_
| this is how isotope is written, identidy each letter and its meaning
a= is the total # of nucleons (atomis mass)
z= is # of protons
| powerpoint # 16
30
1 nucleon has a mass of?
1 amu or dalton
31
by which method are the mass of isotopes and their abundance determined?
experimentally --> ***mass spectrometry ***
32
which instrument is used for mass spectroetry
mass spectrometer
33
what are the 6 steps of mass spectrometization
1) **vaporization** (gass inlet to repeller plate)
2) **ionization**( electron trap)
3) **acceleration** (accelerating plates)
4) **deflection** (magnet)
5) **detection** ( with a detector)
6) **analysis** (through a graph/ ratio mass/charge)
| only for gasses
34
relative abundance represents what?
| ppt 19-20
isotope abundance
35
3 diff types of hydrogens
* 1 p and 0 n = **protium**
* 1 p and 1 n = **deuterium**
* 1 p and 2 n= **triutium**
36
how to dind percent abundance
| measures the natural abundance of each elemets isotopes
(# of atoms of an individual isotope) / (total # of atoms of all isotopes of that element)
x 100
37
Why are atomic masses on the periodic table not whole numbers?
tomic masses are weighted averages of all an element’s isotopes, based on their natural abundances and individual masses.
## Footnote
average mass = atomic weight
38
atomic weight equation
atomic weight = ( (% abundance isotope 1)/100) x (mass of isotope 1) + ( (% abundance isotope 2)/100) x (mass of isotope 2) + ....
| powerpoint #25 # 26
39
What are periods and groups in the periodic table?
Periods are horizontal rows, and groups are vertical columns of elements with similar chemical properties
40
Who developed the periodic table and on what basis?
Dmitri Mendeleev developed the periodic table based on atomic weights, but we now organize it by atomic numbers.
## Footnote
he argues that element properties are periodic functions of their atomic weights, we know that they are period f(x)s of ATOMIC NUMBERS
41
What are the three main types of elements in the periodic table?
Metals, nonmetals, and metalloids.
42
What are common properties of metals?
Metals are
1. conductive,
2. malleable,
3. ductile,
4. and tend to lose electrons to form cations.
43
What are common properties of nonmetals?
Nonmetals are poor conductors and tend to gain electrons to form anions.
44
How are binary molecular compounds named?
Use prefixes (mono-, di-, tri-, etc.) to indicate the number of atoms, and the second element’s name ends in "-ide."
45
What are ionic compounds?
Compounds composed of cations (usually metals) and anions (usually nonmetals) held together by electrostatic attraction.
46
cations
positively charged
47
anions
negatively charged
48
What is Coulomb’s Law?
Coulomb’s Law states that the force of attraction between charged particles increases with greater charge and decreases with distance.
49
What is Avogadro’s number?
6.022 × 10²³, the number of particles in one mole of a substance.
50
How is molar mass calculated?
Molar mass is the sum of the atomic masses of all atoms in a molecule or formula unit.
51
What is percent composition?
Percent composition = [(mass of element in 1 mol of compound / molar mass of compound) × 100].
52
What is an empirical formula?
The simplest whole-number ratio of atoms in a compound.
53
How is molecular formula determined?
Molecular formula = (empirical formula)n, where n = molecular weight / empirical formula weight.
54
What are hydrates?
Compounds that contain a specific number of water molecules per formula unit, denoted as MX*nH₂O.
55
How is the formula of a hydrate determined?
By finding the ratio of moles of water to moles of anhydrous salt.
56
What is the mole concept?
The mole is a unit used to count particles, with 1 mole equaling 6.022 × 10²³ entities.
57
How does ball stick molecule represent amolecule
ball= atom stick= chemical bond
58
what do chemical equations have
reactants and products
59
when writing chemical equation what do we need to inclue
1; balance of molecules/compounds, and 2. and state
| CH_4 (g) + o2 (g)--> CO2 (g) + H2o (l)
60
what is an aqueous solution (aq)
solution in which solven is water
61
all molecular compounds (non ionic) are formed with what
two or more non metals
62
how to name molecular compounds
with prefixes, CO, Carbon monooxide, CO2 carbon dioxide
never write monooxide = always one o, monoxide
| prefixes denote # of atoms in an element
## Footnote
memorize prefixes up to ten
63
n2o4 Name this:
dinitrogen tetraoxide
64
what compounds have metals and nonmetals
ionic
| consist of positive or negative charge
65
what salt is known as an ionic compound
NaCl
66
remember the switch balancing method when balancing
ionic compounds
| denote the charge of a metal with roman numeral
67
removing an electron from an atom produces a
positive charge cation
68
adding an electron to an atom creates
a negative anion
69
for anion name u change the end to
ide
70
a polyatomic ion
group of atoms that stay together and are covalently bonded
| must memorize table
71
A cation polyatomic ion
NH_4 ^+
| ammonium ion
72
Polyatomic ion Cn^-
CYANIDE ION
| ANION GROUP 4A
73
MANY O (oxygen) CONTAINING ANIONS HAVE NAMES ENDING IN
-ATE OR -ITE
74
ionic compounds are
neutral = no NET charge
| amount of + charge = amount of - charge
75
transition metal cations
have more than one charge states
76
where is the oxidation number (charge) of transition metal cations found
the formula
FeCL_2 = chlorine forms a -1 so Fe +2
FeCl3:
| look at ppt
77
metal atom transfers an electron to
non metal atom
78
how are the oppositely charges ions attracted to eachother
through electrostatic forces
79
how do you find the electrostatic forces
through coulomb's law
80
Coloumb Law equation
Electrostatus fore = -k( (n^+E)(N^-E))/ D^2
81
when naming ionic compounds what is named first then second?
first: cation and then anion
82
1 mole =
6.02 x 10^23
83
a mole is just a '
unit, we use it do describe very small things like atoms/molecules ; also known as avogadro's #
84
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