Test Review

Question 0

What are two regions of an atom

Answer 0

nucleus and electron cloud

Question 1

what are the three basic components of an atom

Answer 1

Protons, Neutrons, Electrons

Question 2

how does the nucleus compare to the rest of the atom

Answer 2

it is 10k times larger

Question 3

what is the scanning and tunneling electron microscope (STM used for

Answer 3

it provides 2D and 3D images of atoms

Question 4

what holds electrons and the nucleus together

Answer 4

electric charge

Question 5

unlike charges _________, like charges _________

Answer 5

attract, repel

Question 6

charges on an electron are

Answer 6

negative

Question 7

charges on a proton are

Answer 7

positive

Question 8

charges on a neutron are

Answer 8

neutral

Question 9

why is the overall charge of an atom neutral

Answer 9

of protons = # of electrons

Question 10

when two atoms meet, what parts of the atoms interact

Answer 10

the electrons

Question 11

what are some ways that signals from the atom can be used

Answer 11

they are used to determine the # and type of atoms

Question 12

democritus

Answer 12

coined the term atom

Question 13

john dalton

Answer 13

• first atomic theory

atoms are indivisible, atoms of the same element are alike, all elements are composed of atoms

Question 14

JJ thompson

Answer 14

• plum pudding model

discovered the electron and proved the atom to be divisible

Question 15

Rutherford

Answer 15

discovered the nucleus of an atom with gold foil experiment

Question 16

Niels Bohr

Answer 16

electrons move in definite orbits around the nucleus

Question 17

Robert Millikan

Answer 17

calculated a more accurate value for charge and mass of electrons

Question 18

Goldstein

Answer 18

discovered protons

Question 19

James Chadwick

Answer 19

discovered neutrons

Question 20

Atomic # is a _____ number

Answer 20

whole

Question 21

mass # = ?

Answer 21

of neutrons + # of protons (round off decimal)

Question 22

atomic mass

Answer 22

weighted average of an atoms isotopes

Question 23

isotope

Answer 23

atoms of the same element that differs in the # that changes the mass

Question 24

calculating mass of an element

Answer 24

multiply amu by percent (move decimal 2 places to the left)

add up all results

Question 25

protons are found where

Answer 25

in the nucleus

Question 26

the # of protons in the nucleus is called the

Answer 26

atomic #

Question 27

how are isotopes of an element alike and different

Answer 27

same element type but different masses

Question 28

3 conclusions of rutherfords expriment

Answer 28

• electrons surround the nucleus
• atoms contain empty space
• atoms repel