ch 2

Question 1

Scanning tunneling microscope (STM)

Answer 1

can form images of atoms themselves and pickup/move individual atoms

Question 2

what is an atom

Answer 2

smallest identifiable unit of an element

Question 3

first people to propose that natter was composed of small, indestructible particles

Answer 3

Leucippus and Democritus

Question 4

scientific revolution was marked by what book

Answer 4

On the revolution of heavenly orbs; proposed that the sun, not earth, is at the center of the universe

Question 5

law of conservation of mass

Answer 5

in a chemical reaction, matter is neither created nor destroyed

Question 6

law of definite proportions

Answer 6

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

Question 7

law of multiple proportions

Answer 7

when two elements form 2 different compounds, the masses of element B that combine with 1g of A can be expressed as a ratio of small whole numbers.

Question 8

atomic theory (dalton)

Answer 8

1. each element is composed of atoms
2. all atoms of the same element have he same mass/properties that distinguish them from the atoms of other elements.
3. atoms combine in simple, whole number ratios to form compounds
4. atoms of one element cannot change into atoms of another element.

Question 9

cathode rays

Answer 9

spread of electrons produced when a high electrical voltage is applied between 2 electrodes within a partially evacuated tube.

Question 10

electron

Answer 10

negatively charged, low-mass particle present within all atoms

Question 11

what did Milikan’s oil drop experiment find?

Answer 11

the charge of a single electron: -1.6x10^-19C

Question 12

nuclear theory (Rutherford)

Answer 12

1. most of the atom’s mass and all of its positive charge are in the nucleus
2. most of the volume of the atom is empty space, where negatively charged electrons are dispersed.
3. they are as many negatively charged electrons outside the nucleus as there are positively charged particles within the nucleus, so the atom is electrically neutral.

Question 13

neutrons

Answer 13

neutral particles within the nucleus

Question 14

___and___ have nearly identical masses

Answer 14

protons and neutrons

Question 15

mass of proton vs electron

Answer 15

1.67x10^-27kg vs .00091x10^-27

Question 16

atomic number (Z)

Answer 16

number of protons in an atom’s nucleus

Question 17

isotope

Answer 17

atom with same number of protons but different numbers of neutrons

Question 18

mass number (A)

Answer 18

sum of the # of neutrons and protons in an atom

Question 19

all isotopes of a given element have the same # of

Answer 19

protons

Question 20

ions

Answer 20

atoms can lose or gain electrons to become charged particles

Question 21

cations

Answer 21

positively charged ions

Question 22

anions

Answer 22

negatively charged ions

Question 23

metals are located

Answer 23

the lower left side and middle of the periodic table

Question 24

properties of metals

Answer 24

good conductors of heat and electricity, they are ductile, malleable, shiny, and lose electrons when they energy chemical changes.

Question 25

nonmetals are located

Answer 25

upper right side of the periodic table

Question 26

the dividing line between metals and nonmetals is the zigzag line running from

Answer 26

boron to astatine

Question 27

typical properties of nonmetals

Answer 27

poor conductors of heat/electricity, tend to gain electrons when they undergo chemical changes.

Question 28

many of the elements that lie along the zigzag diagonal line between metals and nonmetals are

Answer 28

metalloids

Question 29

several metalloids are AKA

Answer 29

semiconductors because of their intermediate electrical conductivity

Question 30

metalloids (semiconductors) are useful for making

Answer 30

electronic chips and circuits

Question 31

main group elements

Answer 31

found in the s or p blocks of the periodic table, whose properties tend to be predictable based on their position in the table.

Question 32

transition elements

Answer 32

properties are less predictable based simply on their position in the periodic table

Question 33

family group

Answer 33

each column within the main group regions

Question 34

8A elements

Answer 34

noble gases

Question 35

noble gases are mostly

Answer 35

unreactive

Question 36

group 1A elements

Answer 36

alkali metals

Question 37

____ metals are all reactive metals

Answer 37

alkali

Question 38

2A elements

Answer 38

alkaline earth metals

Question 39

____ metals are not as reactive as ___ metals

Answer 39

alkaline; alkali

Question 40

group 7A elements

Answer 40

halogens

Question 41

____ are very reactive nonmetals

Answer 41

halogens

Question 42

in chem reactions, ___ tend to form cations and ____ tend to form anions.

Answer 42

metals; nonmetals

Question 43

main group elements tend to form ions that have the…

Answer 43

same number of electrons as the nearest noble gas

Question 44

atomic mass

Answer 44

average mass

Question 45

how to find atomic mass

Answer 45

(fraction of isotope 1 x mass of isotope 1)+ (fraction of isotope 2 x mass of isotope 2),,, etc

Question 46

mass spectrometry

Answer 46

a technique that separates particles according to their mass

Question 47

mole

Answer 47

the amount of material containing 6.022x10^23 particles

Question 48

1 mol =

Answer 48

6.022x10^23 particles

Question 49

avogadros #

Answer 49

6.022x10^23

Question 50

the value of the moles is equal to

Answer 50

the # of atoms in exactly 12g of pure carbon-12

Question 51

1 mol atoms=

Answer 51

6.022x10^23 atoms

Question 52

molar mass

Answer 52

mass in grams of 1 mol of atoms of an element (numerically equivalent to the atomic mass of the element in amu)

Question 53

the molar mass of any element is the conversion factor between

Answer 53

the mass (in grams) of that element and the amount (in moles) of that element