01 Matter & Energy

Question 1

What is a subatomic particle

Answer 1

Particles that are smaller than an atom; among such particles protons, neutrons, and electrons are of special significance in chemistry

Question 2

What are atoms composed of

Answer 2

Protons and neutrons held in the nucleus surrounded by an electron cloud

Question 3

How are electrons and protons held together

Answer 3

By an attractive electrostatic force

Question 4

Coulomb’s law

Answer 4

The force of interaction between two charged particles Q1 and Q2 is directly proportional to the product of the two charges and inversely proportional to the distance (d) between the charges squared, where k is the coulomb constant
F = k(Q1Q2/d^2)

Question 5

What is an isotope

Answer 5

Atoms with the same atomic number but different number of neutrons

Question 6

What are a, z and x standing for
A
X
Z

Answer 6

A: Mass number (protons + neutrons)
Z: Atomic number (protons)
X: atomic symbol

Question 7

What is atomic weight

Answer 7

Average of the masses of all isotopes present
AW = (isotope mass) x (fractional natural abundance)

Question 8

What is the law of conversion of mass

Answer 8

No atoms can be transformed into other atoms, and no atoms may be destroyed or created
- in chemical reactions the nuclei of atoms is unchanged

Question 9

What is avgardos number

Answer 9

A conversion factor for relating grams to atomic mass units
The number of atoms in exactly 12g of carbon-12 is equal to 6.022 x 10^23: the number of particles in a mole of any surface

Question 10

What is a mole

Answer 10

A collection containing avogadros number of objects

Question 11

What is an anion

Answer 11

A negatively charged ion
(Gained an electron/s)

Question 12

What is a cation

Answer 12

A positively charged ion
(Lost electrons)

Question 13

Atoms combine to form…

Answer 13

Molecules or extensive solids

Question 14

Molecular Compounds

Answer 14

A compound composed of atoms of two or mo

Question 15

What is energy

Answer 15

The capacity to do work and transfer heat or the ability to make something happen

Question 16

Potential energy

Answer 16

Related to the positioning of an object in relation to other objects

Question 17

Kinetic

Answer 17

Related to the motion of objects

Question 18

First law of thermodynamics

Answer 18

Energy can be converted from one form to another, but cannot be created or destroyed (aka law of energy conversion)

Question 19

Electrostatic

Answer 19

Relating to interactions (force and energy) of stationary charges or fields

Question 20

Which energies dominate chemical processes

Answer 20

Kinetic energy of particle motion and electrostatic potential energy

Question 21

Types of potential energy

Answer 21

Electrostatic, nuclear, or gravitational energy

Question 22

What does the change in internal energy of a system result from

Answer 22

The exchange of heat or work with the surroundings

Question 23

Internal energy of a system

Answer 23

The total energy associated with the system, the sum of all sources of kinetic and potential energy

Question 24

Internal energy changes (ΔE)

Answer 24

(Usually more important)
Directly connected to a physical or a chemical process under consideration

Question 25

Internal energy changes formula

Answer 25

ΔE = q + w

Question 26

-q

Answer 26

Removing heat from a system

Question 27

-w

Answer 27

Having the system do the work

Question 28

ΔE > 0

Answer 28

Q > 0 - heat is added to the system W > 0 - work is done on the system

Question 29

ΔE < 0

Answer 29

Q < 0 - heat is removed from the system W < 0 - work is done by the system

Question 30

What is a state function

Answer 30

Property that depends only on its present state of the system, and is independent of how the state was achieved Examples: P(pressure), T(temperature), E(internal energy), and H(enthalpy) Capital letters are used for state functions

Question 31

What is enthalpy

Answer 31

The heat exchanged with the surroundings under constant pressure

Question 32

In chemical and physical changes occuring under constant pressure, it is indeed quite common that the only work done by that system is due to…

Answer 32

Volume change

Question 33

Endothermic

Answer 33

ΔH > 0 A process in which the system absorbs heat Q > 0

Question 34

Exothermic

Answer 34

ΔH < 0 Heat transfers to the surroundings Q < 0

Question 35

What is light

Answer 35

An electromagnetic wave The “purest” form of energy as it may exist “outside” of matter - on one hand it is an electromagnetic wave traveling with an enormous speed - on the other hand it interacts with matter as a stream of energy packets or photons

Question 36

What is a quantum

Answer 36

The smallest possible amount of a distinct quality

Question 37

Wavelength

Answer 37

The distance between two adjacent peaks or troughs

Question 38

The maximum amplitude of the waves is..

Answer 38

A measure of intensity of the radiation

Question 39

What is radiation

Answer 39

The emission and transmission of energy through space in the form of electromagnetic waves

Question 40

Frequency (v)

Answer 40

The number of cycles that pass a given point per second Expressed as cycles per second or in hertz

Question 41

Properties of waves depends on

Answer 41

Their wavelengths

Question 42

Wavelength range of the visible light spectrum

Answer 42

400-750 nm

Question 43

Photons

Answer 43

What light is a stream of Quantized energy packets

Question 44

Waves in order of increasing wavelength

Answer 44

Gamma rays < x-rays < UV rays < visible light < infrared < microwave < radio

Question 45

Which is more energetic, long waves or small waves

Answer 45

Short waves (large frequency)

Question 46

What is the photoelectric effect

Answer 46

The phenomenon in which only light of proper frequency can eject electrons from an illuminated metal surface

Question 47

What is black body radiation

Answer 47

When solids are heated they emit radiation. The distribution of wavelengths of these electromagnetic waves depends on the temperature of the solid - lower temps: infared frequencies - increasing temps: starts emitting visible light - brown -> red->orange->yellow->white

Question 48

What do BBR and TPEE illustrate

Answer 48

That light can exhibit a “corpuscular” nature in its interaction with nature

Question 49

What is spectroscopy

Answer 49

The study of how light interacts with matter

Question 50

How does light interact with a clear object

Answer 50

All wavelengths of light are transmitted

Question 51

How does light interact with a colored solution

Answer 51

The light of that color is transmitted and the waves of the light of the color absorbed by the medium

Question 52

How does light interact with an opaque material

Answer 52

It reflects the wavelengths

Question 53

What happens when light is emitted

Answer 53

Wavelengths are given off by the system

Question 54

What is a spectrophotometer

Answer 54

A tool used to measure the absorption of light

Question 55

Light energy absorbed by atoms or molecules is converted into…

Answer 55

Various forms of kinetic or potential energy

Question 56

Changes that occur when gamma rays are absorbed

Answer 56

Ionizes atoms and molecules, breaks chemical bonds

Question 57

Changes that occur when x-rays are absorbed

Answer 57

Ionizes atoms and molecules, breaks chemical bonds

Question 58

Changes that occur when UV rays are absorbed

Answer 58

Ionizes atoms and molecules, breaks chemical bonds, promotes electrons to higher energy

Question 59

Changes that occur when visible light is absorbed

Answer 59

Promotes electrons to higher energy

Question 60

What changes occur when infrared rays are absorbed

Answer 60

Increases amplitude of vibrations

Question 61

Changes that occur when microwaves are absorbed

Answer 61

Increases speed of molecular rotations

Question 62

Changes that occur when radio waves are absorbed

Answer 62

Flips the nuclear spin

Question 63

What is the only way that the earth can transfer energy back to space

Answer 63

Radiation

Question 64

About how much incoming light is reflected back, out of the system into space

Answer 64

30%

Question 65

What percentage of incoming light is absorbed by molecules in the atmosphere

Answer 65

19%

Question 66

What percentage of incoming light reaches earths surface

Answer 66

51%

Question 67

What is the greenhouse effect

Answer 67

The “trapping” of energy close to the surface due to greenhouse

Question 68

What is global warming

Answer 68

A gradual increase in the average temperature of the earth due to an imbalance in earths energy cycle

Question 69

When a component color is absorbed by an object, what color does the object appear to be

Answer 69

The complementary color

Question 70

As temperature increases…

Answer 70

Increases: peak frequency, energy of the photon and light intensity Decreases: peak wavelength