Lecture 4

Question 1

Structure of Matter

Question 2

Atomic Terminology

Answer 2

Atomic number= # of protons in nucleus

Atmoic mass number= # of protons + neutrons

Question 3

Isotope

Answer 3

same # of protons but different # of neutrons

Question 4

What are the phases of matter

Answer 4

Solid
Liquid
Gas
Plasma
Phases of same material behaves differently because increase in temperature creaks chemical and physical bonds in materials

Question 5

Phase changes

Answer 5

Ionization - Stripping of electrons changing atoms into plasma

Dissociation- breaking of moecules into atoms

Evaporation- breaking of flexible chemical bonds changing liquid to gas

Melting- Breaking of rigid chemical bonds changing from solid to gas

Question 6

Phases and Pressure

Answer 6

Phase of a substance depends on both temperature and pressure

Often more than one phase is present

Question 7

How is energy stored in atoms?

Answer 7

Electrons in atoms are restricted to particular energy levels

Question 8

Energy Level Transitions

Answer 8

The only allowed changes in energy are those corresponding to a transition between energy levels

Question 9

Structure of matter

Answer 9

Matter is made of atoms, which consits of protons, neutrons and surrounded by a cloud of electrons

Question 10

Phases of matter

Answer 10

Adding heat to substances changes its phase by breaking its chemical bonds

By adding heat to substances it transforms them from solids to liquids by seperating molecules into atoms

Stripping electrons from atoms turns them into Plasma (ionization)

Question 11

How is energy stored in atoms

Answer 11

THe energy level in atoms correspond to piticular energy levels

Atoms lose and gain energy only in amounts that corresponds to particular change in energy levels

Question 12

3 basic types of spectra

Answer 12

Emission Line Spectrum
Continuous Spectrum
Absorption Line Spectrum

Question 13

Continuous Spectrum

Answer 13

Spectrum of a common light bulb spans all visible wavelengths without interruption

Question 14

Emission Line Spectrum

Answer 14

Thin or low density cloud of gas emits light depending on temperature which will then produce a spectrum with bring emission lines

Question 15

Absorption Line Spectrum

Answer 15

A cloud of gas between us and the lightbulb, the gas will absorb the light of specific wavelengths leaving dark absorption lines in the spectrum

Question 16

Continuous, Emission, Absorption

Answer 16

Contiuous spectrum- has a variety of different spectrums on wavelength and frequency (Emitted by dense material)

Emission Line Spectrum - Emission line for particular wavelength or frequencys (Emitted by thin gas)

Absorption Line spectrum
- Dark absorption for wavelengths and frequencies (occurs if light is sent through a thin gas)

Question 17

Chemical Fingerprints

Answer 17

• Each type of atom has a unique set of energy levels
• Each transition corresponds to a unique photon energy frequency and wavelength