Chapter 02: Atoms and Elements

Question 1

Law of conservation of mass

Answer 1

Matter is neither created nor destroyed in a chemical reaction

Mass of reactants = mass of products

Question 2

Law of definite proportions

Answer 2

All samples of a given compound have the same proportions of their constituent elements

Water is always H20

Question 3

Law of multiple proportions

Answer 3

Atoms of two or more elements may combine in different ratios, producing various compounds

Question 4

Subatomic particles

Answer 4

Election (e-) - negative charge, mass is minute

Proton (p) - positive charge, mass = 1840x an electron’s

Neutron (n) - neutral particle, GREATEST MASS

Question 5

Cathode rays

Answer 5

Beam of particles, negatively charged

Question 6

Cathode

Answer 6

Negatively charged electrode

Question 7

Anode

Answer 7

Positively charged electrode

Question 8

Radioactivity

Answer 8

Spontaneous emission of particles and/or radiation

Question 9

Radioactive element

Answer 9

Spontaneously emits radiation

Question 10

Alpha particles

Answer 10

Positively charged particles

Question 11

Beta particles

Answer 11

Negatively charged particles

Question 12

Gamma rays

Answer 12

Neutral charge, high-energy radiation

Question 13

Nuclear theory

Answer 13

Nucleus = most of atom’s mass and all of its positive charge

Empty space = most of the atom

of protons = # of electrons, so atoms are neutral

Question 14

Periodic table

Answer 14

Elements are in order of increasing atomic number

Row = period
Column = group/family

Question 15

Group 1A

Answer 15

Alkali metals

Question 16

Group 2A

Answer 16

Alkaline earth metals

Question 17

Groups XB

Answer 17

Transition metals

Question 18

Groups XB - inserted rows

Answer 18

Inner transition metals

Question 19

Group 7A

Answer 19

Halogens

Question 20

Group 8A

Answer 20

Noble/inert gases

Question 21

Atomic number

Answer 21

Z

Number of protons

Question 22

Mass number

Answer 22

A

Number of protons + neutrons

Question 23

Chemical symbol

Answer 23

X

Chemical abbreviation

Question 24

X-A

Answer 24

Chemical-Mass #

Question 25

Molecule

Answer 25

2+ atoms in DEFINITE arrangement, held together by chemical forces

Question 26

Diatomic molecule

Answer 26

2-atom molecule

Question 27

Diatomic molecules in nature (7)

Answer 27

``` Hydrogen (H) Nitrogen (N) Fluorine (F) Oxygen (O) Iodine (I) Chlorine (Cl) Bromine (Br) ``` H + N through F + F down to I "Have No Fear Of Ice Cold Beer"

Question 28

Polyatomic molecule

Answer 28

>2 atom molecule

Question 29

Polyatomic molecules in nature

Answer 29

Phosphorus (P4) Sulfur (S4) Selenium (Se4) (Oxygen (O3)) (remaining 3 Other Nonmetals angled in diatomic molecules N, O, F, Cl, Br

Question 30

Cation

Answer 30

Positively charged ion

Question 31

Anion

Answer 31

Negatively charged ion

Question 32

Monatomic ion

Answer 32

1-atom ion

Question 33

Polyatomic ion

Answer 33

2+ atom ion

Question 34

Main-group/representative elements

Answer 34

A groups | Properties tend to be largely predictable based on location in table

Question 35

Transition elements

Answer 35

B groups | Properties tend to be less predictable simply based on location in table

Question 36

Metals

Answer 36

``` Solids at room temperature (EXCEPT MERCURY, Hg) Lustrous (shiny) Good conductors of heat/electricity Malleable Ductile High melting points, high densities Tends to lose electrons ``` Form ionic compounds with nonmetals Rarely combine with other metals

Question 37

Metals found in free states (3) | "Noble metals"

Answer 37

Silver (Ag) Platinum (Pt) Gold (Au)

Question 38

Nonmetals

Answer 38

``` Not lustrous (shiny) Poor conductors of heat/electricity Not malleable Not ductile Fairly low melting points & densities Tend to gain electrons ``` Form molecular compounds with each other (and metalloids) Form ionic compounds with metals BROMINE (Br) is liquid at room temperature

Question 39

Metalloids

Answer 39

Properties are between metals and nonmetals Some are semiconductors ``` Boron (B) through Astatine (At) EXCLUDING Aluminum (Al) (and Polonium (Po)) ```

Question 40

Transition metals with predictable charge (3)

Answer 40

Silver (Ag) - Group 1B = 1+ charge Zinc (Zn) - Group 2B = 2+ charge Cadmium (Cd) - Group 2B = 2+ charge

Question 41

Atomic mass

Answer 41

amu Mass of an atom Based on carbon-12

Question 42

Average atomic mass

Answer 42

Weighted average of all naturally occurring isotopes of an element Avg = (amu)(% abundance)+(amu)(% abundance)

Question 43

Mass spectrometry

Answer 43

Separates particles according to mass | Used to determine masses of atoms & % abundances

Question 44

1 mole (Avogadro's number)

Answer 44

6.022 x 10^23 objects

Question 45

Molar mass

Answer 45

Mass of 1 mole of atoms of an element, expressed in grams x amu = x g/mol