C2.1-2.4 Chemistry 1210 - Atoms

What is the first postulate of Dalton's Atomic Theory?

each element is made of extremely small particles called atoms

What is the second postulate of Dalton's Atomic Theory?

all atoms of element are identical, but atoms of one element are diff from those of another element

What is the third postulate of Dalton's Atomic Theory?

atoms of one element can't be changed into atoms of a diff element through chem reactions. Atoms are neither created nor destroyed in chem reactions.

What is the fourth postulate of Dalton's Atomic Theory?

when atoms of more than one element combine, compounds are formed. A compound always has the same number and kind of atoms

What two laws of chem combination known at the time did Dalton's Theory explain?

law of constant composition, law of conservation of mass

What is the law of constant composition?

in a given compound, the relative numbers and kinds of atoms are constant

What is the law of conservation of mass?

mass of reactants in a chem reaction must equal the mass of the products

Dalton utilized his theory to deduce what?

law of multiple proportions

What is the law of multiple proportions?

if two elements A and B combine to form more than one compound, the masses of B that can combine w/ a given mass of A are in the ratio of small whole numbers

Experiments showed that cathode rays are...

deflected by electric or magnetic fields in a way consistent w there being a stream of neg electrical charge

JJ Thomson observed...

cathode rays are same regardless of identity of cathode material

Thomson described cathode rays as...

streams of neg charged particles called electrons

Thomson was able to determine the ratio of the electron's...

charge to its mass

Robert Milikan suceeded in measuring...

charge of an electron which is 1.602 x 10^-19

What is the relative charge of an electron?


What is the relative charge of an proton?


What is the relative charge of an neutron?


What is on the x axis for a mass spectrometer? y axis?

atomic mass (amu), signal intensity