the study of matter, its composition, properties, and transformation
Mass and occupied space.
what is composition made of?
rocks, minerals, everything of our crust
Hard? Soft? Density?
boiling, freezing, and melting point
involves into a new substance "transformation"
unique set of characteristics that identify a matter
L- Loose packed
H- Tightly packed
independent of the quantity of matter ( color, odor, density, temperature)
dependent on the quantity of matter ( mass, volume, heat)
sig fig rules
- non- zero digits are always significant
- any zeros between two sig digits are sig
- a final zero or trailing zero in the decimal portion are signfigant
sig fig rules (adding/ subtraction)
- count the number of sig. figs in the decimal portion in the problem
- add or subtract
- round the answer to the last number of places in the decimal portion
sig fig rules ( multi./ Dividing)
- the least number of sig. figs in the problem is the number who determines the answers sig. figs
What do we use acceleration to find?
how much matter is in an object
what is weight?
refers to the force of gravity on an object
what is the law of conversion?
summarize all scientific observations about matter
smallest particle of an element that has properties of that element and can enter into a chemical combination
-discovered by democritus- believed atmons are made of particles that could not be broken down
consist of two or more atoms joined together by strong forces called chemical bonds
constant composition, pure ( nacl, h20,)
is composed of two or more types of matter that can be present in varying amounts and can be separated by physical change ( evaporation)
a mixture that varies from point to point ( sand water)
the properties of each substance don't change
also called a SOLUTION, exhibits a uniform composition and appears visually the same throughout
(Sports drinks).. same amount of sugar to water throughout ever drink
how close to the measurement is to the true value
is how consistent results are when measurements are repeated
difference between chemical change and physical
chemical change atoms rearrange, physical change molecular structure stays the same
physical change characteristics
- reacts with acid
-reacts with water to form gas
-reacts with base
-All matters are made of tiny indivisible particles called "atoms"
- Atoms of same element are similar, atoms of different elements are different
-Elements combine to form compounds, combination of atoms of different element, produce compound atom
-Created by john Dalton
Conservation of mass
mass is constant (does not change and can not be broken or destroyed) "here to stay"
law of definite proportion
elements combine in fixed proportion by mass to form compound.
( they also combine in certain ways, never changes)
ALSO, it is fixed because you need to take the whole atom, never can take a portion
example: 1g hydrogen and 8g oxygen and 9g water) FIXED BY MASS
law of multiple proportion
-two elements can form more than one compound
example: hydrogen and carbon
-> one can produce carbon monoxide and another can produce carbon dioxide, etc...
negative (another word)
(reduction because it gains an electron)
"LEO says GER"
positive (another word)
(Oxidation because it looses an electron)
"LEO says GER"
who discovered the x-ray
who discovered the electron
J.J thompson with the help of the cathode ray tube ( figured it out when the rays bent)
what is the charge of cathode rays?
Who was Robert Millikan?
"oil drop experiment" which measured the charge of the electron
who discovered radioactivity?
(something that is giving energy)
what aided the discovery of radioactivity?
who discovery the gamma ray?
who designed the mass spectrometer
What does the mass spectrometer do ?
- gives relative mass of particles
-invented neutron because there was missing mass in the negative/ positive atom
what year was the neutron discovered ?
who carried out the gold foil experiment ?
this helped discover the nucleus
( the alpha particle hit the middle and bounced all around
length x length
length x length x length
mass/volume = kg/m^3
distance/ time = m/s
velocity/ time = m/s^2
mass x acceleration= newtons
word and energy
kg x (m^2/S^2) = joule
energy/ time = watts
force/ area= Pascal
what does the atomic number represent ?
number of protons in the nucleus of an atom
the average mass of all isotopes of an element
atoms of same element with different mass number
what does M-A=N represent ?
mass- atomic number = neutrons
who was niels bohr ?
figured out why electrons stay away from the nucleus
oxidation and reduction
leo says ger
what is oxidation state ?
is the gain or loosing of electrons
who was dimitri mendelveev ?
put together the periodic table
who was Lothar Meyer ?
organized them into rows (periodic law) and properties of elements
Properties of elements are periodic function of atomic number
What are rows called and what are columns called?
R- called period run from top to bottom (But side to side) 1 to 7
C- called groups run from left to right (down if looking for something)
what does group A represent ?
represents elements or main group elements
what does group B represent?
*Have roman numerals *
Characteristics of metal ?
Solid, shiny matter, good conductors
- tend to loose electrons (cation)
Characteristics of non- metals ?
Liquid, gas, dull, opaque ( not transparent)
-gain electrons (Anion)
Characteristics of Metalloid ?
How are the elements labeled by groups?
- Alkai metals (expect hydrogen)
- Alkaine metals (earth metals )
- Boron family
- Noble gases or inhert gases
What is a compound ?
two or more elements bound together producing a specify structure
what is Ionic compound ?
Metal with non- metal
- transfer electrons from metal to non- metal
- generally soluble in water
- high melting point
(REMEBER TICS) - TRANSFER IONIC... COVALENT SHARE
what is a covalent compound?
- Non-metal and non- metal
- electrons are shared
- low melting point
- low boiling point
how to label transitional metals
Cu copper (II)
use roman numerals
how to label ionic compound
-combine the two elements together
-shows the simplest form of ratio of ions
question what is the oxidation number of cr in k(2)cr (2)O (7)
(answer is 6+)
-because you have to make the whole equation equal zero.
Take the charge at normal state and mult. by how many of the element you have and then subtract or add to get your answer
what is the charge of
group 4= -4,+4
group 8=0 they don't loose or gain electrons
question: the mercury content of a stream was believed to be above the minimum considered safe- 1 part per billion (ppb) by weight. An analysis indicated that the concentration was 0.68 parts per billion. What quantity of mercury in grams was present in 15.0L of the water, the density of which is 0.998 g/ml? (1ppb Hg= 1ng Hg/ 1g water)
It's just grams of mercury per one billion grams of water. You use the density of water to multiply by the volume to find the mass of water, then multiply the ppb to cancel out the grams of water and leave you with grams of HG
what is the formula for Cu (I) Bromide
how to label a covalent compound
-represented by molecular formula
-DO NOT reduce
how to table covalent compound (examples)
Co- carbon monoxide
co2- carbon dioxide
n(2) o(4)- dinitrogen tetraoxide
sF(6)- sulfur hexafluride
- find the mass of each element in the problem
- multiple the mass by how many elements there are
-add up all masses
- divide one elements mass by the total and times by 100
what is the percent composition of cu So(4) x 5 (h2o)
total weight= 249.72 amu
*should equal 100 or 99.99
difference between empirical and molecular for c(6) H(8) 0(6)
molecular =c(6) H(8) 0(6) ( not simplified) ( Covalent)
empirical = c(3) h(4) 0(3)( Simplified) ( Ionic)
What is avogadro's number
6.02 x 10^23 = 1 mol
* it is important because every element represents how much atom in a certain element
* this is your conversion factor
what is the mass in grams for 3.20 x 10^21 atoms of Cu?
Answer= 3.20 x 10^21 x 63.55 / 6.02 x 10^23 = answer (3 sig figs)
what is mass of ( in grams ) of 0.150 C(3) H(8)?
what is the empirical formula of 40.00% carbon, 6.63% hydrogen, 53.37 oxygen ?
answer: c1 h2 01
* you might have to multiply if the number is not close to a whole number (2.33) multiply by any number to get actually numbers without decimals
Cr2 O2 7
How to convert grams to mol
Grams/ Molecule or Grams/ formula (weight)
to convert mol to gram
mol x formula ( weight)
What is the rule about rounding when trying to find CxHyOz
*You can no round if the number is 2.33, you must multiply to find a better number
what does one mol represent
6.02 x 1023
How to convert percentage to give answer to how much of each element.
1. change the percentage
Example= 40.00 to 40.00
2. Divide by it atomic mass
3. Take the answer of all elements and divide by the smelled one
4. The division after step three is your answer