Chapter 3

Question 1

three types of subatomic particles

Answer 1

electrons
protons
neutrons

Question 2

electron

Answer 2

subatomic particle that possesses a negative (-) electrical charge

• smallest, in terms of mass
• determine the chemical properties of an atom

Question 3

proton

Answer 3

subatomic particle that possesses a positive + electrical charge
- carry the same amount of charge as electrons

Question 4

neutrons

Answer 4

a subatomic particle that has no charge associated with it

• neutral
• same mass as protons
• 2000 times heavier than electrons

Question 5

nucleus

Answer 5

• where all protons and all neutrons are located

- very small, dense, positively charged center of an atom

Question 6

nucleus is always positively charged why?

Answer 6

because it contains positively charged protons

- it houses positive protons and neutral neutrons

Question 7

• almost over 99.9% of the mass of an is concentrated where?

Answer 7

nucleus

Question 8

small size of nucleus coupled with large amount of an atom causes?

Answer 8

materials to be extremely dense

Question 9

nucleon

Answer 9

any subatomic particle found in the nucleus of an atom

- protons and neutrons both nucleon

Question 10

what determines the volume or size of the atom

Answer 10

the motion of the electrons in the extranuclear region determines the volume

Question 11

electron cloud

Answer 11

the volume occupied by the electrons

Question 12

atomic number

Answer 12

the number of protons in it nucleus

Z atomic number = number of protons = number of electrons = Z

Question 13

mass number

Answer 13

the sum of the numbers of protons and neutrons in its nucleus
- gives number of subatomic particles present in nucleus
mass number = number of protons + number of neutrons = A

Question 14

calculating number of subatomic particles

Answer 14

number of protons = atomic number = Z
number of electrons = atomic number = Z
number of neutrons = mass number = A-Z

Question 15

element

Answer 15

a pure substance in which all atoms present have the same atomic number

Question 16

isotopes

Answer 16

atoms of an element that have the same number of protons and electrons but different number of neutrons
- always have same atomic number and different mass number

Question 17

most elements found in nature exists in what form

Answer 17

isotopic form

Question 18

characteristics of isotopes of an element

Answer 18

• have same chemical properties, but their physical properties are often slightly different

Question 19

why does isotopes have the same chemical properties and different physical properties

Answer 19

• have the same number of electrons (chemical)

- have different numbers of neutrons - different masses (physical)

Question 20

isotope symbol

Answer 20

mass number -> A
chemical symbol -> S
atomic number -> Z

Question 21

elements atomic mass

Answer 21

weighted-average mass of isotopes of an element

Question 22

atomic mass

Answer 22

calculated average mass of the isotopes of an element

Question 23

periodic law

Answer 23

when elements are arranged in order of increasing atomic number, elements with similar properties occur at periodic regularly recurring interval

Question 24

periodic table

Answer 24

a graphical display of the elements in order of increasing atomic number in which elements with similar properties fall in the same column of the display

Question 25

group in periodic table

Answer 25

vertical column of elements

Question 26

period in periodic table

Answer 26

horizontal row of elements

Question 27

nonmetal

Answer 27

an element characterized by the absence of the properties of luster, thermal conductivity, electrical conductivity and malleability

Question 28

the only nonmetal found as a liquid at room temperature are?

Answer 28

bromine and mercury

Question 29

Subatomic particle

Answer 29

very small particle that are the building blocks from which atoms are made of

Question 30

electron shell

Answer 30

a region of space about a nucleus that contains electrons that have approximately the same energy and that spend most of their time approximately the same distance from the nucleus

Question 31

electron subshell

Answer 31

region of space within an electron shell that contains electrons that have the same energy

Question 32

subshell size type letters and maximum electrons

Answer 32

``` s = 1 p = 6 d = 10 f = 14 ```

Question 33

electron orbitals

Answer 33

region of space within an electron subshell where an electron with a specific energy is most likely to be found - orbitals maximum of electron is 2 ex - 14f has 7 orbitals

Question 34

electron configuration

Answer 34

statement of how many electrons an atom has in each of its subshell

Question 35

two most common classification systems of elements

Answer 35

1. system based on selected physical properties of the elements - described as metal or non metal 2. based on electron configurations of the elements - described as noble gas, representative, transition, or inner transition elements

Question 36

noble gas elements

Answer 36

found in the far right column of the periodic table - non metals - all gases at room temperature - little tendency to form chemical compound - electron config ending in p6 (not helium)

Question 37

noble gases: the most unreactive of all elements

Answer 37

helium, neon, and argon

Question 38

representative elements

Answer 38

- all elements of the s and p areas of the periodic table, with exception of the noble gases - complete s or partial p

Question 39

transition elements

Answer 39

- all elements of the d area of the periodic table | - d subshell

Question 40

inner transition elements

Answer 40

- all elements of the f area of the periodic table | - have in f sub

Question 41

stable nucleus

Answer 41

a nucleus that does not easily undergo change

Question 42

unstable nucleus

Answer 42

a nucleus that spontaneously undergoes change

Question 43

radioactivity

Answer 43

the radiation spontaneously emitted from an unstable nucleus

Question 44

radioactive atom

Answer 44

an atom with an unstable nucleus from which radiation is spontaneously emitted

Question 45

radioactive decay

Answer 45

the process whereby an unstable nucleus undergoes change as a result of the emission of radiation - not all decay at same rate

Question 46

half-life

Answer 46

the time required for 1/2 of any given quantity of a radioactive substance to undergo decay

Question 47

alpha particle

Answer 47

particle in which two protons and two neutrons are present 4 4 a = He 2 2

Question 48

beta particle

Answer 48

- particle whose charge and mass are identical to those of an electron o ß -1

Question 49

gamma ray

Answer 49

- form of high energy radiation without mass or charge 0 Y 0

Question 50

parent nucleus

Answer 50

- nucleus that undergoes decay in a radioactive decay process

Question 51

daughter nucleus

Answer 51

nucleus that is produced as a result of a radioactive decay process

Question 52

alpha particle decay equation

Answer 52

A 4 A-4 X-->a + Y Z 2 Z-2

Question 53

balanced nuclear equation

Answer 53

sums of the subscript (atomic numbers or particle charges) on both sides of the equation are equal, and the sums of the superscripts (mass number) on both sides of the equation are equal