test 1 Flashcards
dimensional analysis
changing quantities by units of measure mkhddcmmnp
heterogenous mixture
Each component keeps its original properties each sample of the mixture will be different not uniform
homogenous mixture
completely uniform in composition and portion of components each sample of the mixture is exactly the same
chemical change
when matter undergoes changes in composition
physical change
alter a substance without changing its composition
mixture
A physical blend of two or more substances which retain their own identity
compound
combination of two or more atoms can be separated chemically
solution
homogeneous or heterogeneous a combining of 2 or more different substances
atomos
indivisible
smallest particle
atom
atomic theory
- all elements are composed of indivisible particles called atoms
- All atoms of the same element are identical in properties
- Atoms cannot be created or destroyed or subdivided by any chemical reaction
- Atoms of different elements can physically mixer chemically combine in simple whole number ratios to form chemical compounds
-  Chemical reactions can occur when atoms are separated join or rearranged
what part of the atomic theory is wrong
that atoms cannot be divided because they are made of electrons neutrons and protons
law of conservation mass
atoms cannot be created or destroyed during chemical or physical changes
problem with bohrs solar system model
The electrons are not being moved around the nucleus in constant speeds because they would implode
quantum mechanical model
based on the solar system model electron stay in the spot in the space between the nucleus they don’t move called the electron cloud model
 electron
negative charge e-. in space around the nucleus. 9.11x10^-28 g
proton
positive charge p+. in the nucleus. 1 AMU
neutron
no charge n°. in the nucleus. 1 AMU
nucleus
small dense positive
composed of protons and neutrons
electrons fly around the nucleus in empty space
thomson
discover the electron with the cathode ray tube and the plum putting model electron spread evenly through the positive charge of an atom
milikan
Calculated the charge of the electron with the oil drop
schrodinger
created the electron cloud model and has the current model based on a 90% probability of finding an electron in space around the nucleus
bohr
Solar system model electrons orbiting the nucleus at constant speed wrong because they would include
rutherford
develop the theory of the nucleus with the gold foil experiment
metals property
shiny malleable ductile and good conductors
nonmetals
hard brittle gases poor conductors and hydrogen is a nonmetal
metalloids
Seven solids boron silicon arsenic Hilarion astatine germanium and antimony. Si Ge a great semi conductors of electricity at high temp
bohrs energy levels
Level one can hold two electrons
level 2 8 electrons
level 3 18 electrons
level 4 32 electron
mendeleev
Am down similar properties across
mosley
similar properties down
atomic number across
flipped the table
law of definite proportions
a given chemical compound always contains the same elements in the exact same proportions by mass.
law of multiple proportions
when two different compounds are composed of the same elements the ratio of the mass of the elements will always be whole numbers
cathode ray tube
thompson discovered the electron with this. The rays move from the negative end to the positive end of the tube realizing the rays were made of negatively charged particles called electrons
gold foil exp
by Rutherford. Using a thin sheet of gold foil he shot alpha particles through the foil some passed through and others were deflected. atoms are mostly empty space and are positively charged
