Chapter 2 - Atoms, Molecules, and Ions

Question 1

Law of conservation of mass

Answer 1

mass is neither created nor destroyed

Question 2

Law of definite proportion

Answer 2

a given compound always contains exactly the same proportion of elements by mass

Question 3

Law of Multiple proportions

Answer 3

when two elements form a series of compounds, the ratios of the masses of the second element that combine with 1 g of the first element can always be reduced to small whole numbers.

Question 4

Dalton’s Atomic Theory

Answer 4

1. Each element is made of tiny particles called atoms.
2. The atoms of a given element are identical; the atoms of different elements are different in some fundamental way or ways.
3. Chemical compounds are formed when atoms of different elements combine with each other. A given compound always has the same relative numbers and types of atoms.
4. Chemical reactions involve reorganization of the atoms- changes in the way they are bound together. The atoms themselves are not changed in a chemical reaction.

Question 5

Avogadro’s Hypothesis

Answer 5

At the same temperature and pressure, equal volumes of different gases contain the same number of particles.

Question 6

plum pudding model

Answer 6

atoms are electrons embedded in a a cloud of positive charge

Question 7

radioactivity

Answer 7

spontaneous emission of radiation.
3 types:
gamma, beta (electron), and alpha particles (2+)

Question 8

Rutherford’s experiment

Answer 8

disproved plum pudding model. shot alpha particles at gold and had some widely deflected. Only reasonable conclusion was a dense, positive nucleus in the center of the atom.

Question 9

mass number

Answer 9

total number of protons and neutrons

Question 10

covalent bonds

Answer 10

share electrons
forms molecules
nonmetals with nonmetals

Question 11

ion

Answer 11

atom or group of atoms that has a net positive or negative charge

Question 12

ionic bonding

Answer 12

force of attraction between oppositely charged ions (anions and cations)
ionic solid = solid consisting of oppositely charged ions is called an ionic solid

Question 13

naming ionic compounds

Answer 13

cation + anion
cation keeps the metal’s name
anion is nonmetal’s name ending with -ide
(Hydrogen can be 1+ or 1- charge).

Question 14

Roman numerals

Answer 14

indicate the positive charge of a cation

Question 15

acids

Answer 15

molecules with one or more H^+ ions attached to an anion.