Chem- Ch 1

Question 1

Proton

Answer 1

Positive charge

Mass: 1 amu

Question 2

Neutron

Answer 2

No charge

Mass: 1 am

Question 3

Electron

Answer 3

Negative charge

Negligible mass

Question 4

Nucleus

Answer 4

Protons + neutrons

Electrons move around nucleus

Question 5

Atomic number

Answer 5

protons = #electrons

Number of protons in a given element

Question 6

Mass number

Answer 6

Sum of element’s protons and neutrons

Question 7

Atomic mass

Answer 7

Sum of an elements protons and neutrons

Question 8

Isotopes

Answer 8

Atoms of given element with different mass numbers

-different. Inner of neutrons

Question 9

Isotopes of H

Answer 9

Protium: H-1
Deuterium: H-2
Tritium: H-3

Question 10

Atomic weight

Answer 10

Weighted average of the naturally occurring isotopes of an element

Question 11

Rutherford

Answer 11

Postulated atom had a dense positively charged nucleus that made up only a small fraction of the atom’s volume

Question 12

Bohr model of atom

Answer 12

Dense positively charged nucleus surrounded by electrons that move around in orbits with distinct energy levels

Question 13

Quantum

Answer 13

Energy difference between energy levels

-described by Planck

Question 14

Quantization

Answer 14

Electron can only exist only at certain energy levels

-energy level of electron increases the farther it is from nucleus

Question 15

Atomic absorption spectrum

Answer 15

Electron to jump from a lower energy level to a higher one, it must absorb precise amount of energy needed
-unique for every element

Question 16

Atomic emission spectrum

Answer 16

When electron returns from excited to ground state

-emit energy exactly equal to energy difference between two levels

Question 17

E = hf

Answer 17

E = hc/ lamda

H = Planck's constant, J•s
C = 3 x 10^8
E = energy, J

Question 18

Quantum mechanical model

Answer 18

Electrons travel in localized orbitals (not defined orbits)

Question 19

Orbital

Answer 19

Region of space around the nucleus defined by the probability of finding an electron in the region

Question 20

Heisenberg uncertainty principle

Answer 20

Impossible to know both an electron’s position and momentum exactly at the same time

Question 21

Quantum numbers

Answer 21

Numbers that completely describe an electron in an atom

Question 22

Principle quantum number, n

Answer 22

Describes the average energy of a shell

-max number of electrons in a shell = 2n^2

Question 23

Azimuthal quantum number, l

Answer 23

Describes the subshells within a given principle energy level

• l=0– s, l=1– p, l=2– d, l=3– f
• refers to shape and number of subshells in an energy level

Question 24

Magnetic quantum number, ml

Answer 24

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

2l + 1 possibilities
Ex) s, px, py, pz

Question 25

Spin quantum number, ms

Answer 25

Indicates the spin orientation of an electron in an orbital

Question 26

Electron configuration

Answer 26

Uses spectroscopic notation | Ex) 1s^2, 2s^2, 2p^6

Question 27

Pauli exclusion principle

Answer 27

No two electrons in a given atom possess the same set of four quantum numbers

Question 28

Aufbau principle

Answer 28

Electrons fill from lower to higher energy subshells | -each subshell will fill completely before electrons enter next one

Question 29

Cations

Answer 29

Positively charged ions

Question 30

Anions

Answer 30

Negatively charged ions

Question 31

Hunds rules

Answer 31

Subshells with multiple orbitals (p, d, f) fill electrons so that every orbital in a subshells gets one electron before any of them gets a second

Question 32

Paramagnetic

Answer 32

Have unpaired electrons that align with magnetic fields | -attract to magnet

Question 33

Diamagnetic

Answer 33

Have all paired electrons - cannot easily be realigned - repelled by magnets