Chapter 2

Question 1

What is an atom?

Answer 1

the smallest quantity of matter that still retains properties of matter

Question 2

What is an element?

Answer 2

a substance that cannot be broken down into two or more simpler substances by any means

Question 3

What is radiation?

Answer 3

the emission and transmission of energy in the form of waves

Question 4

What are cathode rays?

Answer 4

radiation beams emitted from the negatively charged plates in an evacuated tube when a high voltage is applied

Question 5

What is Coulomb’s Law?

Answer 5

Like charges repel one another; opposite charges attract one another

Question 6

Who proposed that rays were actually streams of negatively charged particles and determined the charge to mass ratio of the particles (1.76e8)?

Answer 6

J.J Thompson

Question 7

What are electrons?

Answer 7

negatively charged subatomic particles found outside the nucleus of all atoms

Question 8

What is the charge of a single electron (Milikan)?

Answer 8

-1.6022e-19

Question 9

What is the mass of a single electron (Milikan)?

Answer 9

9.10e-28

Question 10

What are x-rays (Rontgen)?

Answer 10

electromagnetic radiation emitted when cathode rays are directed to glass or metal

Question 11

What is radioactivity (Becquerel)?

Answer 11

the spontaneous emission of particles or radiation from unstable nuclei

Question 12

What are the 3 types of radiation produced by radioactive substances?

Answer 12

1) Alpha: consist of positively charged particles
2) Beta: electrons
3) Gamma rays: high energy radiation (no charge)

Question 13

What is a nucleus (Rutherford)?

Answer 13

The central core of the atom that contains the protons and neutrons

Question 14

What is a proton (Rutherford)?

Answer 14

a positively charge particle in the nucleus of an atom

Question 15

What is the charge of a proton?

Answer 15

1.6022e19 C

Question 16

What is the mass of a proton?

Answer 16

1.6762e-24

Question 17

What is the mass of a neutron (Chadwick)?

Answer 17

1.67493e-24

Question 18

What is an atomic numbers?

Answer 18

The way that elements are identified; identifies the number of protons and electrons

Question 19

What are nucleons?

Answer 19

neutrons and protons

Question 20

How do you find the mass number?

Answer 20

Mass Number (A) = number of protons (Z) + number of neutrons

Question 21

What are isotopes?

Answer 21

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

Question 22

How are chemical properties identified?

Answer 22

by the number of protons and electrons

Question 23

How is the stability of a nucleus determined?

Answer 23

by the difference between Coulombic repulsion and short-range attraction

Question 24

What is the main factor in determining if a nucleus is stable?

Answer 24

the neutron to proton ratio; even numbers of protons and neutrons have more stable nuclei than odd numbers of protons and neutorns

Question 25

What is the average mass(the atomic mass)?

Answer 25

the average mass between all the isotopes of an element

Question 26

What are ions?

Answer 26

positively charged species formed by collisions of high-energy electrons and gaseous molecules

Question 27

What are the vertical columns of the periodic table called?

Answer 27

families/groups

Question 28

What are the horizontal rows on the periodic table called?

Answer 28

periods

Question 29

How does the periodic table change from right to left?

Answer 29

the chemical properties of the elements change from metal to nonmetal

Question 30

What are groups of the periodic table?

Answer 30

1) alkali metals 2) alkaline earth metals 16) chalcogens 17) halogens 18) noble gases 3-11) transition metals

Question 31

What is a mole?

Answer 31

the amount of a substance that contains as many elementary entities (atoms) as there are atoms in exactly 12 g of carbon-12

Question 32

What is Avogadro's number?

Answer 32

the number of atoms in exactly 12 g of carbon-12 (6.022e23)

Question 33

What is molar mass?

Answer 33

the mass (g) of one mole of the substance; any element's molar mass(g) = its avg. mass (amu)