Atomic and Molecular Structure

Question 1

All atoms of an element show similar __ ___ and cannot be further __ __ by chemical means

Answer 1

chemical properties, broken down

Question 2

All compounds are composed of atoms of more than one ___. For any given compound, the ratio of the numbers of atoms of any two elements present is either an ___ or a __ ___

Answer 2

element, ratio, simple fraction

Question 3

A given chemical reactions involves only the ___, ___ or ___ of atoms, it does not result in the ___ or ___ of atoms

Answer 3

separation, combination, rearrangement, creation, destruction

Question 4

the mass of one proton

Answer 4

atomic mass unit / dalton

Question 5

Different isotopes of one element have different numbers of __ but the same number of ___

Answer 5

neutrons, protons

Question 6

weighted average of all isotopes of an element found naturally on earth

Answer 6

standard atomic weight

Question 7

The idea that energy emitted as electomagnetic radiation from matter comes in discrete bundles called quanta

Answer 7

quantum theory

Question 8

Bohr assumed that the atom consisted of a ____ around which an electron travelled in a _ ___, and that the __ __ acting on the electron as it revolved around was the __ __ between the positively charged proton and the ____ charged electron

Answer 8

nucleus, circular orbit, centripetal force, electrical force, negatively

Question 9

Bohr combined ____ ___ and __ _, and postulated that the __ __ of an electron is ____. Thus, the ___ of the electron also changes in discrete amounts.

Answer 9

quantum mechanics, classical physics, angular momentum, quantized, energy

Question 10

A value of __ energy was assigned to the state in which the proton and electron were ____ completely, meaning there was no ___ force between them. Therefore, the electron in any of its __ __ in the atom would have a ____ ___ as a result of attractive forces between the electron and proton.

Answer 10

zero, separated, attractive, quantized states, negative energy

Question 11

The energy of the electron is related to its __ ___. The smaller it is, the ___ the energy state of the electron. The smallest orbit an electron can have corresponds to n = 1, which is the __ ___ of the ___ electron.

Answer 11

orbital radius, lower, ground state, hydrogen

Question 12

At ___ ___ the majority of atoms in a sample are in the ground state. However, electrons can be ___ to higher energy levels by ____ or other energy. These electrons will return rapidly to ground state while emitting energy in the form of ____. The __ ____ of these photons can be determined.

Answer 12

room temperature, excited, heat, photons, electromagnetic energy

Question 13

The different ___ in an atom will be excited to different __ ___. When these electrons return to their ground states, each will emit a photon with a ____ characteristic of the specific transition is undergoes. These produce a ____ ___, where each line corresponds to a specific ___ ____. Because each element can have its electrons excited to different distinct energy levels, each possess a unique __ __ __, which can be used as a fingerprint

Answer 13

electrons, energy levels, wavelength, line spectrum, electronic transition, atomic emission spectrum

Question 14

The group of hydrogen emission lines corresponding to transitions from upper levels n > 2 to n =2; 4 wavelengths in the visible region

Answer 14

balmer series

Question 15

group of hydrogen emissions lines corresponding to transitions between upper levels n > 1 to n = 1 (transitions in UV region)

Answer 15

lyman series

Question 16

Excitation of electrons results in energy ___ at specific ___. Every element also has a __ ___, and the wavelengths correspond directly to the wavelengths of ___, since the energy difference between levels remains ___. Absorption spectra can be used in the identification of elements present in a __ __ sample

Answer 16

absorption, wavelength, absorption spectrum, emission, unchanged, gas phase

Question 17

Now, electrons are described as being in a state of __ __ within regions of space around the nucleus called ____.

Answer 17

rapid motion, orbitals

Question 18

states that it is impossible to simultaneously determine the momentum and the position of an electron

Answer 18

heisenberg uncertainty principle

Question 19

says that no two electrons in a given atom can possess the same four quantum numbers

Answer 19

pauli exclusion principle

Question 20

The principle quantum represents the ___ where an electron is present in an atom. The max n that can be used to describe the electrons of an element at its __ ___ corresponds with that elements ___ on the periodic table. The larger the value of n, the higher the __ __ and the ___ of the electron’s orbit. The difference in energy between ___ ___ decreases as the distance from the nucleus ___.

Answer 20

shell, ground state, row, energy level, radius, adjacent shells, increases

Question 21

The angular momentum quantum number tells us the ___ of the orbitals and refers to the ___ that occur within each principle energy level. The greater the value of l, the greater the ___ of the subshell. However, the energies of subshells from different __ __ __ may overlap.

Answer 21

shape, subshells, energy, principle energy levels

Question 22

The magnetic quantum number describes the ____ of the orbital in space. It specifies the particular orbital within a -__ where an electron is likely to be found at a given point in ___. The ___ and ___ of each orbital are dependent upon the subshell in which the orbital is found

Answer 22

orientation, subshell, time, shape, energy

Question 23

the spin quantum number defines the intrinsic ___ __ of a particle. Whenever two electrons are in the same ___, they must have opposite spins, and are referred to as ____. Electrons in different orbitals with the same ml values are said to have ___ spins.

Answer 23

angular momentum, orbital, paired, parallel

Question 24

the rule that subshells are filled from lowest to highest energy and each subshell will fill completely before electrons begin to enter the next one

Answer 24

aufbau principle

Question 25

_____ rule is used to rank subshells by increasing energy. It states that the lower the sum of the first and second quantum numbers, the ___ the energy of the subshell. If two subshells possess the same value, the value with the lower __ value has lower energy and will fill first

Answer 25

n+l, lower, n

Question 26

States that within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins

Answer 26

hund’s rule

Question 27

If a material has ___ electrons, a __ __ will align the spins of these electrons and weakly attract the atom to the ___. These materials are said to be ___. Materials that have no ___ electrons and are slightly ____ by a magnetic field are said to be ___.

Answer 27

unpaired, magnetic field, field, paramagnetic, unpaired, repelled, diamagnetic