Exam 1 Ch 3- Atoms

Question 1

greek atom composed of 4 substances-

Answer 1

earth, water, air, & fire

Question 2

greek atom modified by 4 basic essences

Answer 2

wet, dry, hot, & cold

Question 3

greeks used the term atom meaning-

Answer 3

“indivisible” (not cut)

Question 4

rutherford atom-

Answer 4

discovered nucleus

Question 5

Dalton Atom-

Answer 5

-1808 John Dalton, English school teacher, published a book summarizing his experiments
-elements composed of identical atoms that reacted the same way chemically
-all atoms looked alike, constructed alike, & reacted alike

Question 6

Demitri Mendeleev-

Answer 6

-showed elements arranged in order of increasing atomic mass
-elements arranged into 8 groups
-all elements in same group react in similar fashion & have similar physical properties

Question 7

Thomson Atom-

Answer 7

-only difference between atoms of 1 element & atoms of another was their mass
-in late 1890’s he described (cathode ray (electrons)) atoms looking like “plum pudding”
-pudding was a shapeless mass of uniform positive electrification
-# of electrons was thought to equal quantity of positive electrification because atom was known to be electrically neutral

Question 8

Bohr’s Atom-

Answer 8

-1913 Bohr’s model was miniature solar system in which electrons revolved about nucleus in prescribed orbits/energy level
-development of high-energy particle accelerators, structure of atomic nucleus is slowly being mapped & identified

Question 9

nuclear structure-

Answer 9

nucleons, photons, & neutrons composed of quarks held together by gluons

Question 10

considered fundamental particles of an atom-

Answer 10

-electron
-proton
-neutron

Question 11

AMU-

Answer 11

actual mass of a number

Question 12

valence shell-

Answer 12

outermost shell can hold 8 electrons

Question 13

nucleus contains particles called-

Answer 13

nucleons

Question 14

2 types of nucleons-

Answer 14

-protons
-neutrons
-atomic mass # for each is 1

Question 15

atom is mostly-

Answer 15

empty space

Question 16

electron orbits are in groups of-

Answer 16

shells

Question 17

shells help reveal how atoms-

Answer 17

react chemically

Question 18

number of protons determine-

Answer 18

-chemical behavior of an atom
-chemical element

Question 19

electrons can exist only in-

Answer 19

certain shells which represent different binding energies

Question 20

in a normal state, atoms are-

Answer 20

electrically neutral

Question 21

electric charge of an atom is-

Answer 21

0

Question 22

ionization-

Answer 22

removal of an orbital electron from an atom

Question 23

electron arrangement-

Answer 23

-2n^2 (n = shell #)
-max # of electrons that can exist in a shell

Question 24

electron binding energy-

Answer 24

the larger & more complex the atom, the higher the binding energy for electrons in any given shell

Question 25

chemical symbol-

Answer 25

alphabetic abbreviation for elements

Question 26

chemical properties-

Answer 26

determined by electrons # & arrangement

Question 27

Z number-

Answer 27

-atomic #
-# of protons

Question 28

A number-

Answer 28

atomic mass #

Question 29

isobar-

Answer 29

atomic nuclei that have the same atomic mass (A#), but different atomic number (Z#)

Question 30

isotone-

Answer 30

atoms that have the same # of neutrons (A#), but different # of protons (Z#)

Question 31

isomer-

Answer 31

same atomic # (Z#) & same atomic mass (A#)

Question 32

molybdenum-

Answer 32

target material for mammogram units

Question 33

tungsten-

Answer 33

target material in diagnostic units

Question 34

barium & iodine-

Answer 34

positive contrast media

Question 35

barium & iodine-

Answer 35

positive contrast media

Question 36

beta emission-

Answer 36

electron like particle ejected from the nucleus

Question 37

alpha emission-

Answer 37

ejection of 2 protons & 2 neutrons from the nucleus

Question 38

radioactive half-life-

Answer 38

time required for quantity of radioactivity to be reduced to 1/2 its original value

Question 39

particulate ionizing radiation-

Answer 39

-alpha- from heavy radioactive nuclei
-beta- from radioactive nuclei

Question 40

electromagnetic ionizing radiation-

Answer 40

-x-rays- from electron cloud
-gamma rays- from radioactive nuclei

Question 41

atomic mass-

Answer 41

-expressed in AMU
-1/12 the mass of C12

Question 42

electron-

Answer 42

-has 1 unit of negative charge
-mass of 0.000549 AMU

Question 43

neutron-

Answer 43

-no electric charge
-mass of 1.00867 AMU

Question 44

proton-

Answer 44

-1 unit of positive charge
-mass of 1.00728 AMU

Question 45

covalent bonding-

Answer 45

electron sharing

Question 46

ionic bonding-

Answer 46

attracted by electrostatic charge

Question 47

atom-

Answer 47

smallest form of an element that has the characteristics of that element

Question 48

molecule-

Answer 48

smallest form of a compound that has characteristics of that compound

Question 49

radioactivity-

Answer 49

emission of particles & energy in order to become stable

Question 50

radioactive decay/disentigration-

Answer 50

abnormally excited atoms spontaneously emits particles & energy & transforms itself into another atom in an effort to reach stability

Question 51

radioisotopes-

Answer 51

isotopes that are radioactive