Chapter 2

Question 1

of Dalton’s atomic theory

Answer 1

1. matter is made of atoms
2. atoms of the same element are identical -wrong
3. atoms of different elements differ in chemical behavior
4. chemical compounds form of atoms of two or more different elements
5. atoms are neither created nor destroyed

Question 2

law of multiple proportions

Answer 2

when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small whole numbers

Question 3

the law of definite proportions (or Proust’s Law)

Answer 3

all samples of a pure compound contain the same elements in the same proportions by mass

Question 4

Thomsons contribution to Chem

Answer 4

used Cathode ray tube to discover electron. He also described an atom as plum pudding because he did not know about the nucleus

Question 5

Millikans contributions to chem:

Answer 5

used oil drop experiments to determine that atoms can be separated

Question 6

Ernest Rutherfords contributions to chem:

Answer 6

used a beam of high-speed, positively charged alpha particles and deduced that atoms have a large amount of empty space and a positively charged center- proton

Question 7

atomic number

Answer 7

number of protons (also the number of electrons if atom is neutral)

Question 8

mass number

Answer 8

number of protons and neutrons

Question 9

Ion

Answer 9

when charges are not equal

Question 10

Cation

Answer 10

+1 charge

Question 11

anion

Answer 11

-1 charge

Question 12

Isotope

Answer 12

atoms that contain the same number of protons but different numbers of neutrons

Question 13

Isomer

Answer 13

compounds with the same chemical formula but different structures

Question 14

Avogadro’s number

Answer 14

6.022 × 10^23/mol.