Ch 2: Atoms, Ions, and Molecules

Question 1

What is Dalton’s Atomic Theory?

Answer 1

everything is composed of atoms, atoms of the same element are all identical, atoms of different elements are different, compounds are composed of atoms of two or more different elements, atoms in compounds combine in whole number ratios

Question 2

What does the law of definite proportions state?

Answer 2

different samples of the same compound always contain that compound’s constituent elements in the same proportion by mass

Question 3

What does the law of multiple proportions state?

Answer 3

when more that one compound contains the same elements the ratio of the ratio of the elements is a small whole number

Question 4

What does the law of conservation of mass state?

Answer 4

matter can be neither created nor destroyed

Question 5

What is radiation?

Answer 5

the emission and transmission of energy through space in the form of waves

Question 6

J.J. Thomson

Answer 6

he used a cathode ray tube and his knowledge of electromagnetic theory to determine the ratio of electric charge to the mass of an individual electron

Question 7

R. A. Millikan

Answer 7

he succeeded in measuring the charge of the electron (-1.6022 x 10^-19 C) and the mass (9.10 x 10^-28 g) by examining the motion of single tiny drops of oil that picked up static charge from ions in the air.

Question 8

What is radioactivity?

Answer 8

the spontaneous emission of particles and/or radiation

Question 9

What are Alpha (a) rays?

Answer 9

positively charged particles, called a particles, and therefore are deflected by the positively charged plate

Question 10

What are Beta (weird B) rays?

Answer 10

they’re electrons and are deflected by the negatively charged plate

Question 11

What are Gamma (Y) rays?

Answer 11

y rays have no charge and are not affected by an external field

Question 12

E. Rutherford

Answer 12

he gave us the modern picture of an atom by using very thin foils of gold and other metals as targets for a particles from a radioactive source

Question 13

What is an atomic number (Z)?

Answer 13

the number of protons in the nucleus of each atom of an element

Question 14

What is a mass number (A)?

Answer 14

the total number of neutrons and protons present in the nucleus of an atom of an element

Question 15

What are isotopes?

Answer 15

atoms that have the same atomic number (Z) by different mass numbers (A)

Question 16

How are isotopes identified?

Answer 16

with their element and mass numbers

Question 17

What are periods on the periodic table?

Answer 17

horizontal rows

Question 18

What are groups or families on the periodic table?

Answer 18

vertical columns

Question 19

Group 1 elements are called:

Answer 19

alkali metals

Question 20

Group 2 elements are called:

Answer 20

alkaline earth metals

Question 21

Group 17 elements are called:

Answer 21

halogens

Question 22

Group 18 elements are called:

Answer 22

noble gases

Question 23

What is a molecule?

Answer 23

an aggregate of at least two atoms in a definite arrangement held together by chemical forces (chemical bonds)

Question 24

What are diatomic molecules?

Answer 24

molecules containing only two atoms

Question 25

What are polyatomic molecules?

Answer 25

molecules containing more than two atoms

Question 26

What is an ion?

Answer 26

a charged atom

Question 27

What is a cation?

Answer 27

an ion with a net positive charge

Question 28

What is an anion?

Answer 28

an ion whose net charge is negative

Question 29

What is a monatomic ion?

Answer 29

an ion containing only one atom

Question 30

What is a polyatomic ion?

Answer 30

an ion containing more than one atom

Question 31

What does a chemical formula express?

Answer 31

the composition of molecules and ionic compounds in terms of chemical symbols

Question 32

What are considered inorganic compounds?

Answer 32

ionic compounds, molecular compounds, acids and bases, and hydrates

Question 33

What is an acid?

Answer 33

a substance that yields hydrogen ions (H+) when dissolved in water

Question 34

What are oxoacids?

Answer 34

acids that contain hydrogen, oxygen, and another element (the central element)