lecture 1

Question 1

mixture

Answer 1

contains particles of more than one specific atom or molecule-solutions

Question 2

types of mixtures

Answer 2

homogeneous and heterogeneous

Question 3

democritus

Answer 3

first to think of an atom

Question 4

antoine lavoisier

Answer 4

discovered law of conservation of mass

Question 5

joseph proust

Answer 5

law of definite proportions (in H2O, water is always 88.8% oxygen and 11.2% hydrogen by mass)

Question 6

john dalton

Answer 6

4 postulates

Question 7

4 postulates

Answer 7

1) each element is composed of tiny particles called atoms.
2) all atoms of a given element are identical, and all atoms of different elements are different.
3) atoms are not created or destroyed in chemical reactions.
4) compounds are formed when atoms of different elements combine with one another.

Question 8

J. J. Thompson

Answer 8

electrons, charged particles in ray tube w electric field and found they would go towards the positive field

Question 9

earnest rutherford

Answer 9

nucleus, gold foil experimemt

Question 10

rutherfords model

Answer 10

1) nucleus is a very small positively charged core containing protons and neutrons.
2) negativity charged electrons are extremely small and occupy the vast majority of the atom’s volume

Question 11

mass number

Answer 11

top number. M = p + n

Question 12

atomic number

Answer 12

A = # of p & e

Question 13

isotope

Answer 13

same element, but different number of neutrons-doesnt change chemical behavior, just changes mass

Question 14

average atomic weight equation

Answer 14

(mass # X % abundance) + (mass # X % abundance)…= average mass

Question 15

mass % equation

Answer 15

mass % element = (# of atoms of element) X (element’s atomic mass)
—————————————————X 100
(formula weight of compound)

Question 16

john dalton

Answer 16

law of multiple proportions

Question 17

pure sample

Answer 17

contains particles of one specific atom or molecule-elements or compounds