chem 103-- chap 2

Question 1

definition of element

Answer 1

fundamental substance that can’t be chemically changed or broken down

Question 2

how many elements are there?

Answer 2

118

Question 3

what is the most abundant element in the human body and on the earth’s crust

Answer 3

oxygen

Question 4

periodic table definition

Answer 4

organized chart of elements with their names, symbols, and other info

Question 5

who arranged the elements in a table to show that there were more elements to be found

Answer 5

Dmitri Mendeleev

Question 6

what are periods

Answer 6

organized 7 horizontal rows

Question 7

what are groups in the periodic table

Answer 7

18 vertical colomns

Question 8

how are the elements arranged in the periodic table

Answer 8

they are grouped by similar chemical properties

Question 9

property definition

Answer 9

any characteristic to describe or identify matter

Question 10

what are examples of properties

Answer 10

volume, amount, odor, color, temp

Question 11

what is an intensive property

Answer 11

temp and melting point don’t depend on amount of the sample

Question 12

what is an extensive property

Answer 12

(length and volume) depend on amount and sample size

Question 13

what is a physical property

Answer 13

Any property you can see, smell, touch, hear or otherwise detect and measure without performing a chemical reaction

Question 14

chemical property

Answer 14

characteristics involve a change in chemical makeup

Question 15

what are the elements in group 1A named?

Answer 15

alkali metals

Question 16

what are the elements in group 2A named?

Answer 16

alkaline earth metals

Question 17

what are the elements in group 7A named?

Answer 17

halogens

Question 18

what are the elements in group 8A named?

Answer 18

Noble gases

Question 19

where are the nonmetals location

Answer 19

mostly on the right side of the table, besides helium

Question 20

what elements are best conductors of electricity

Answer 20

metals

Question 21

noble gas porperties

Answer 21

colorless gas
low reactivity
helium and neon don’t combine w/ any other element

Question 22

halogen properties

Answer 22

only found in nature w/ another element

colorful, cohesive metals

Question 23

alkaline earth metal properties

Answer 23

silvery metals

less reactive than 1A

Question 24

alkali properties

Answer 24

high reactivity
react with water rapidly
(hydrogen is in group one, but isn’t a alkali)

Question 25

What is the largest category of elements

Answer 25

metals

Question 26

How many semi metals are there? and where are they located?

Answer 26

7 elements and they are diagonal on the right side between the metals and nonmetals

Question 27

what are chemical compounds

Answer 27

atoms of different elements joining together in different ways to yield a vast number of different substances

Question 28

what is a chemical formula

Answer 28

lists the symbols of it's constitutes and uses subscripts to indicate number of atoms EX: NaCl

Question 29

what is a chemical equation

Answer 29

reactant substances undergoing changes written out to see the change EX: 2HgO --> 2Hg + O2

Question 30

law of mass conservation definiton

Answer 30

mass is neither created nor destroyed in chemical reactants

Question 31

law of definite proportions definiton

Answer 31

different samples of a pure chemical compound always contains the same proportions of the elements by mass

Question 32

law of multiple proportions definiton

Answer 32

elements can combine in different ways to form different chemical compounds, whose mass ratios are simple WHOLE NUMBER multiplier of each other

Question 33

what is Dalton's theory

Answer 33

elements are made up of atoms same mass of elements = same element atoms never change, just their ratios

Question 34

what are atoms

Answer 34

tiny particles that make up elements

Question 35

what is Thompson's experiment

Answer 35

Cathode-ray tube-- high voltage electric currents going from a negative electrode, to a positive electrode. Proposed electrons were in the metals

Question 36

3 things that affect magnetic deflection

Answer 36

strength of deflecting magnet size of negative charge on electron mass of electron

Question 37

what is an ionic bond

Answer 37

share electrons by transferring 1+ of them

Question 38

what are ions

Answer 38

charged particles

Question 39

what are cations

Answer 39

positive ions, (by losing electrons)

Question 40

what are anions

Answer 40

(by gaining electrons)

Question 41

Are cations typically metals or nonmetals?

Answer 41

Metals

Question 42

are anions typically metals or nonmetals?

Answer 42

nonmetals

Question 43

what is an ionic solid

Answer 43

equal numbers of ions packed together with opposite attractions EX: Na+ & Cl-

Question 44

what are polyatomic ions?

Answer 44

charged covalent groups of atoms

Question 45

what are binary ionic compounds

Answer 45

2+ elements in a ionic compound

Question 46

When writing a binary ionic compound, how do you write it?

Answer 46

positive ion 1st negative ion 2nd add "ide" at the end

Question 47

what two categories fall under pure substances

Answer 47

elements and chemical compounds

Question 48

what experiment did Millikan conduct

Answer 48

mist voltage experiment and found electron mass

Question 49

What was Rutherford's experiment?

Answer 49

found nucleus in atoms by shooting alpha particles through foil & and having some of them reflect

Question 50

nucleus defintion

Answer 50

tiny central core in atom

Question 51

what is the nucleus composed of?

Answer 51

Protons and electrons. elements differ in size of nucleus based on how many they have

Question 52

proton defintion

Answer 52

positively charged; opposite charge of electron

Question 53

neutron defintion

Answer 53

no charge, equal mass to protons

Question 54

atomic number defintion

Answer 54

number of protons IN the nucleus and number of neutrons AROUND the nucleus EX: helium= atomic number 2= 2 protons

Question 55

mass number defintion

Answer 55

number of protons and neutrons in an atom

Question 56

isotope defintion

Answer 56

identical atomic number but diff. mass and diff. amounts of neutrons

Question 57

atomic mass defintion

Answer 57

specific atom's mass; numerically close to mass number

Question 58

atomic weight defintion

Answer 58

average of natural isotope masses of an element

Question 59

how do you mathematically find atomic weight of an element?

Answer 59

(element 1 mass)(abundance) + (element 2 mass)(abundance)

Question 60

what is a mole

Answer 60

SI unit for amount

Question 61

what is molar mass

Answer 61

amount of mass of an element in grams to moles

Question 62

mixture

Answer 62

blend of 2+ substances w/o chemical change

Question 63

chemical compound

Answer 63

atoms of different elements combining into a new substance

Question 64

chemical bonds

Answer 64

electrons forming connections to join atoms together into compounds

Question 65

covalent bonds

Answer 65

2 atoms sharing 2+ electrons

Question 66

what is the most common bond type?

Answer 66

covalent bonds

Question 67

what is a molecule

Answer 67

result of 2+ atoms joined together by covalent bonds

Question 68

what do ball-stick models show?

Answer 68

atoms connected together by covalent bonds

Question 69

what do space filling models show?

Answer 69

show molecular shape but not bonds

Question 70

structural formula

Answer 70

shows specific connections

Question 71

diatomic molecules

Answer 71

molecules whose same atoms are held together by covalent bonds

Question 72

what are diatomic elements

Answer 72

``` H2 N2 O2 F2 Cl2 Br2 I2 ```