Units 16-17

Question 1

What were the two questions that the Bohr model did not answer?

Answer 1

1. Why were there special orbits?
2. Why didn’t the electrons radiate when they were in these orbits?

Question 2

Which model addresses the questions in the Bohr model?

Answer 2

Quantum model

Question 3

What kind of waves do electrons moving around an atom set up?

Answer 3

Standing waves

Question 4

True or False: 3D standing waves have nodes and antinodes

Answer 4

True

Question 5

What does the amplitude of the standing wave of an electron to nucleus relationship represent?

Answer 5

The likelihood of finding an electron at that location.

Question 6

When is the probability the highest to find an electron, a node or anti-node?

Answer 6

Anti-node

Question 7

What is the probability of finding an electron in a node?

Answer 7

Zero

Question 7

True or False: Since the standing wave pattern is stationary (within an atom) the probability of locating electrons at any given location doesn’t change with time

Answer 7

True

Question 8

Why don’t electrons radiate in the quantum model?

Answer 8

Because they are confined to a static space, which means they are not accelerating around in an orbit. If they’re not accelerating, they’re not radiating.

Question 9

How do electrons move?

Answer 9

In an orbital
Standing waves of probability

Question 10

True or False: Electrons move in an orbit around a nucleus of an atom.

Answer 10

FALSE

Question 11

What is an orbital?

Answer 11

A standing wave giving the probability of finding an electron in various locations around the nucleus of an atom.

Not an orbit, just an “orbital” space where an electron COULD be found inside an atom.

Question 11

True or False: Electrons orbit the nucleus of an atom like planets orbit a star

Answer 11

False

Question 12

True or False: There are different shapes of orbitals

Answer 12

True

Question 13

What determines the shape of the orbital?

Answer 13

The number of standing waves and how those waves extend to space.

Question 14

What are spherical harmonics?

Answer 14

The standard shapes of the orbitals

Question 15

True or False: An electron in an atom has a fixed wavelength.

Answer 15

True

Question 16

How does the quantum model explain why orbitals are discrete?

Answer 16

Because fixed wavelengths can only be set up (to create standing waves) at the exact right distance from the nucleus.

Imagine the string being shaken to create standing waves. They can only be created if they are WHOLE integers and the exact right distance apart to create nodes and anti-nodes.

Question 17

What is spectroscopy?

Answer 17

The study of the brightness and wavelengths of the different frequencies of light emitted by excited atoms and ions.

Question 18

True or False: The electron can be found inside the nucleus of an atom.

Answer 18

TRUE
But it’s extremely unlikely given the sizes.

Question 19

How many types of orbitals are in the “p” orbital set?

Answer 19

3
Oriented on x, y, and z axis

Question 20

What gives shape to atoms and molecules?

Answer 20

The directionality and orientation (cardinal points) of the lobes of an orbital

Question 21

How many kinds of “d” orbitals are there?

Answer 21

5 total
4, four leaf clovers
1 dumbell with a donut

Question 22

True or False: The Quantum model can also apply to the nucleus of an atom

Answer 22

True

Question 23

What characteristics are the same within orbitals of the same type?

Answer 23

General form

Question 24

What characteristics are DIFFERENT within orbitals of the same type?

Answer 24

Size, energy, radial shape

Question 25

What is radial shape?

Answer 25

The cross section of an orbital that has been sliced through the center.

Question 26

What is a shell?

Answer 26

A group of orbitals having similar energies and sizes.

Question 27

True or False: Electrons in higher-numbered orbitals are more likely to be found farther from the nucleus.

Answer 27

True

Question 28

True or False: Higher numbered orbitals also possess more energy than lower numbered orbitals of the same type

Answer 28

TRUE

Question 29

Why do orbitals farther away have greater electrical potential energy?

Answer 29

Because the electrons are farther away from the protons. (opposite charges)

Question 30

How many characteristics does an electron orbital have in an atom?

Answer 30

1. Shape 2. Shell 3. Spin

Question 31

What is spin in the context of electrons and orbitals?

Answer 31

The direction of the electron's magnetic field. It is NOT an electron spinning within an orbital.

Question 32

True or False: Electrons have magnetic fields

Answer 32

True

Question 33

How many directions can the spin of an electron be in?

Answer 33

2 Up and down

Question 34

What is an eV?

Answer 34

Electron volt A small amount of energy used to measure energies of particles in atoms.

Question 35

What does the quantum model say about the movement of electrons within their orbitals?

Answer 35

That the places where they're found doesn't change with time. So the electrons are not moving or accelerating (and therefore, not radiating)

Question 36

True or False: There's a limit to how many waves can pass through a single point at one time.

Answer 36

False

Question 37

True or False: Due to an electron's wave nature, an infinite number of electrons can occupy the same orbital.

Answer 37

False

Question 38

What is the exclusion principle?

Answer 38

The rule that two electrons cannot be in exactly the same state in an atom. In other words, no two electrons in the same atom can have exactly the same shell, orbital, and spin values.

Question 39

True or False: The exclusion principle says that even when two electrons have a probability of being in the same place at the same time, they cannot be in the same state.

Answer 39

True

Question 40

What is an electron's "state"?

Answer 40

Defined as its specific shell, orbital, and spin

Question 41

True or False: An electron state is like an address with three pieces - shell, orbital, spin

Answer 41

True

Question 42

Does a high energy or low energy orbital fill up first?

Answer 42

Low energy, closest to the nucleus.

Question 43

True or False: In the quantum model, when an electron moves from a high energy orbital to a lower energy orbital, it releases the energy difference as a photon, just as with the Bohr model.

Answer 43

True

Question 44

True or False: Orbitals are probability patterns.

Answer 44

True

Question 45

How are the probability patterns of orbitals calculated?

Answer 45

By measuring the interactions between the negative electrons and positive nucleus.

Question 46

What percentage of the time can we find electrons inside the orbitals?

Answer 46

90%

Question 47

What is electronic structure?

Answer 47

The shorthand notation for what orbitals are occupied in a particular atom (looks like chem stuff)

Question 48

How many electrons can be in a single orbital?

Answer 48

2

Question 49

Which type of orbital is shaped like a sphere?

Answer 49

s orbital

Question 50

True or False: An electron in a standing wave/orbital is moving like a particle.

Answer 50

FALSE It's moving like a wave

Question 51

What happens to the number/kind of orbitals as the shell number increases?

Answer 51

Another kind of orbital will be added onto the ones in the shell below.

Question 52

What is the study of chemistry?

Answer 52

The study of how atoms interact

Question 53

What is the name for the electrical connections between atoms?

Answer 53

Bonds

Question 54

Why do bonds form?

Answer 54

Because the positively charged nuclei attract not only their electrons, but also the electrons of OTHER atoms.

Question 55

What is an element?

Answer 55

A substance that cannot be broken down further.

Question 56

True or False: Elements contain only one TYPE of atom

Answer 56

True

Question 57

What is the law of constant composition?

Answer 57

Substances contain a fixed, definite proportion of elements by mass.

Question 58

What is atomic theory?

Answer 58

The model that matter is made up of atoms

Question 59

What are the 5 postulates of atomic theory?

Answer 59

1. Matter is composed of indivisible atoms 2. An element contains only a single kind of atom, and all within that element are identical in every respect. 3. Atoms of different elements have different mass and chemical reactivity. 4. Chemical COMPOUNDS are composed of two or more atoms joined together in fixed ratios. 5. Chemical REACTIONS are the rearrangement of atoms to form different compounds.

Question 60

What are some flawed assumptions in Dalton's atomic theory (which is otherwise correct)?

Answer 60

Atoms ARE divisible Atoms of elements CAN differ slightly in mass without changing behavior. 4th assumption is true for most but not all substances.

Question 61

Physical properties

Answer 61

Melting, boiling temperature, density, ionization potential, etc.

Question 62

Chemical properties

Answer 62

Properties associated with the chemical reactivity of a material.

Question 63

Who constructed the periodic table?

Answer 63

Mendeleev

Question 64

What is the periodic law?

Answer 64

The properties of the elements are a periodic function of their atomic masses. (all the numbers of the periodic table must be filled in, no gaps, there were predictable patterns)

Question 65

What is the highest atomic number of naturally occurring atoms?

Answer 65

92

Question 66

How do scientists create new elements?

Answer 66

Protons are accelerated to very high speeds and collided into heavier atoms. Sometimes those collisions form new atoms.

Question 67

How long do MOST man-made elements live before decomposing?

Answer 67

millionths of a second

Question 68

What is the atomic number?

Answer 68

How many protons are in a nucleus (equal to electrons)

Question 69

What are the three major categories of the periodic table?

Answer 69

Metals Nonmetals Synthesized (man-made)

Question 70

What are metals?

Answer 70

Good electrical and thermal conductors Hammered into thin sheets or drawn into fine wires (malleable and ductile)

Question 71

What are nonmetals?

Answer 71

Elements that do not conduct electricity

Question 72

What percentage of the known elements are metals?

Answer 72

3/4

Question 73

True or False: All but one of the metallic elements are solid at room temperature.

Answer 73

True Mercury... weird

Question 74

Which category on the periodic table shows the most variety in their properties?

Answer 74

Non-metals Gases, liquids, solids at room temperature. Colored vs. colorless

Question 75

What's another name for families?

Answer 75

Groups

Question 76

What are families or groups of elements?

Answer 76

Elements grouped because they have similar chemical properties, and the same number of valence electrons.

Question 77

Are families listed vertically or horizontally on the periodic table?

Answer 77

VERTICALLY

Question 78

What are the horizontal rows called on the periodic table?

Answer 78

Periods

Question 79

What are periods?

Answer 79

Within a given row, physical and chemical properties change systematically from element to element.

Question 80

What are the main group elements?

Answer 80

The set of metal and nonmetal elements designated with A column headings. They have valence electron configurations involving only s and p electrons

Question 81

Transition metals

Answer 81

B column headings. Valence electron configurations involving d electrons.

Question 82

What is a common feature of the actinide series?

Answer 82

They're all radioactive.

Question 83

Atomic size

Answer 83

Estimate of the volume occupied by an atom. This number is obtained from the density of the solid state of the element.

Question 84

Ionization energy

Answer 84

The amount of energy needed to completely remove an electron from an atom. Varies with atomic number.

Question 85

What does it mean for an atom to have a low ionization energy?

Answer 85

It is easy to strip an electron from an atom and ionize it. It takes LOW energy to turn an atom into an ion. They lose electrons easily.

Question 86

True or False: All metals have low ionization energies.

Answer 86

True

Question 87

What is the reason metals are shiny and electrically conducting?

Answer 87

Because they have low ionization energies.

Question 88

What family has the highest ionization energy?

Answer 88

Noble gases (helium, neon, argon, etc.)

Question 89

True or False: Noble gases don't tend to interact with other atoms because their ionization energies are so high.

Answer 89

True

Question 90

What are valence electrons?

Answer 90

One or more electrons in the OUTERMOST populated shell of an atom.

Question 91

What determine an element's chemical reactivity?

Answer 91

Valence electrons

Question 92

True or False: Atoms with completely filled shells are unreactive.

Answer 92

True

Question 93

True or False: Repulsive forces between the electrons in an atom changes their energy levels.

Answer 93

TRUE

Question 94

Atomic weight

Answer 94

the average atomic mass of all naturally-occurring forms of a particular atom.

Question 95

What is a subshell?

Answer 95

S and p orbitals in a shell.

Question 96

What determines what type of atom it is?

Answer 96

The number of protons

Question 97

True or False: Ionized atoms have unequal numbers of protons and electrons.

Answer 97

True

Question 98

True or False: When a shell or subshell is full, the atom is more stable

Answer 98

True

Question 99

True or False: Valence electrons are part of the unfilled shells.

Answer 99

True

Question 100

Why do families of elements have similar physical and chemical properties?

Answer 100

Because valence electrons determine reactivity/reactions, and they have the same number of valence electrons.