Ch 1: Atomic Structure Flashcards Preview

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Flashcards in Ch 1: Atomic Structure Deck (20):
1

atomic number

number of protons in a given element

2

mass number

sum of the element's protons and neutrons

3

atomic mass

essentially equal to the mass number, being the sum of protons and neutrons

4

isotopes

atoms of a given element (same atomic number) that have different mass numbers. they differ in the number of neutrons

most identified by element and mass number
ex: carbon-12

5

three isotopes of hydrogen go by

protium
deuterium
tritium

6

atomic weight

weighted average of the naturally occuring isotopes of an element

Periodic table lists atomic weights not atomic masses

7

quantum

the enerrgy difference between energy levels of the revolving electrons around the nucleus in the Bohr Model of the atom

8

the energy of an electron ____ the farther it is from the nucleus

increases

9

quantization

there is not an infinite range of energy levels available for an electron; they can only exist at certain energy levels

10

atomic emission spectrum

every element has s characteristic spectrum when electrons fall from excited state back to ground and sometimes the emitted corresponds to a frequency in the visible light range

11

quantum mechanical model

says electrons do not travel in defined orbits but rather are localized in orbits; regions of space around nucleus where there is a probability of finding e-

12

Heisenberg uncertainty principle

impossible to know both the electrons position and momentum exactly at the same time

13

4 quantum numbers are

n, l, ml, ms

14

principal quantum number (n)

average energy of the shell

15

azimuthal quantum number (l)

subshells within a given principal energy levels (s,p,d, and f)

16

magnetic quantum number (ml)

specifies particular orbital within a subshell where an electron is likely to be found at given moment in time

17

spin quantum number (ms)

indicates the spin orientation (+/- 1/2) of an electron in an orbital

18

Hund's Rule

every subshell with multiple orbitals (p,d, and f) fill electrons so that every orbital in a subshell gets one electron before any get a second

19

paramagnetic

unpaired electrons that align with magnetic fields, attracting the material to a magnent

20

dimagnetic

all paired electrons, which cannot easily be realigned; they are repelled by magnets