Exam 1: Intro/Matter/Atoms

Question 1

What is the first scientific discipline with theoretical principals that are also applied to something?

Answer 1

Chemistry

Question 2

What are 2 other examples of theoretical disciplines?

Answer 2

Physics and Math

Question 3

Define chemistry

Answer 3

The study of matter and the changes it undergoes

Question 4

T/F There is no crossover between different chemical disciplines

Answer 4

False

Question 5

What do physical chemists focus on?

Answer 5

They are “overglorified” mathematicians; they want to understand chemical systems from a theoretical framework

Question 6

What do analytical chemists study?

Answer 6

Study methods for identification and quantification of matter within a chemical system; everything they do is applied science but they also do some theoretical science as well
Ex: Using instruments and medical diagnostics like MRIs/CT scans/etc.

Question 7

What do inorganic chemists study?

Answer 7

Substances that are derived from all of the elements EXCEPT carbon

Question 8

What do organic chemists study?

Answer 8

Carbon-based compounds

Question 9

What do biochemists study?

Answer 9

Chemical processes that occur within living systems

Question 10

Define matter

Answer 10

Anything that has mass and occupies space

Question 11

What comprises matter?

Answer 11

Everything

Question 12

Describe the differences in shape between solids, liquids, and gases

Answer 12

Solids - defined shape
Liquids - less defined shape; requires a container
Gases - no shape whatsoever

Question 13

What can we do to gases and somewhat do to liquids?

Answer 13

Compress them

Question 14

What happens to the volume and pressure when you compress a liquid or gas?

Answer 14

Compression decreases the volume and increases the pressure

Question 15

T/F When a cylinder of gas (that’s pressurized) goes empty, there is no more gas left in the cylinder

Answer 15

False; when the cylinder goes “empty” the pressure inside the take is equalized inside the tank vs outside of the tank but the gas is not entirely gone

Question 16

What occurs when you continue to compress a gas?

Answer 16

It can liquify

Question 17

Can you compress a liquid?

Answer 17

Yes, but not as much as gas

Question 18

Can solids be compressed?

Answer 18

Not really; if you continue to compress a solid, you will just break it

Question 19

Define atoms

Answer 19

Submicroscopic particles that are the fundamental “building blocks” of all matter (they can be the same type of different types combined)

Question 20

What 3 things are found within an atom?

Answer 20

Protons, neutrons, electrons

Question 21

What are the charges for protons, neutrons, and electrons?

Answer 21

Protons - positively charged
Neutrons - neutral
Electrons - negatively charged

Question 22

What makes up most of the mass of an atom?

Answer 22

Protons and neutrons

Question 23

Where are protons and neutrons found?

Answer 23

In the nucleus of the atom

Question 24

Where are electrons found?

Answer 24

Surrounding the nucleus in orbitals in the electron cloud

Question 25

How can we tell how many protons are in an atom?

Answer 25

Look at the atomic number; this number tells us the identity of the atom and thus the amount of protons

Question 26

What does the amount of neutrons tell us?

Answer 26

The isotope of the element we are looking at

Question 27

Why are isotopes important?

Answer 27

They are important because they can be used for looking for diseases Ex: Using Iodine or Fluorine w/ scans to light up specific parts

Question 28

What do electrons tell us about an atom?

Answer 28

Electrons tell us the charge of the atom

Question 29

Can you change the charge of an electron?

Answer 29

Yes; by losing or gaining an electron, you can change whether it is positively/negatively charged When you lose an electron = the charge becomes positive = CATIONS Ex: Metals like to lose electrons When you gain an electron = the charge becomes negative = ANIONS Ex: Gases/Non-metals like to gain electrons

Question 30

What are molecules?

Answer 30

Two or more atoms joined in a specific arrangement

Question 31

What are pure substances?

Answer 31

Substance that is comprised of a single type of matter

Question 32

What 2 things can pure substances be broken down into?

Answer 32

Elements - can not be broken down further Compounds - can be broken down even further

Question 33

What is a mixture?

Answer 33

Matter that consists of two or more pure substances

Question 34

What are the 2 types of mixtures?

Answer 34

Homogenous mixture - mixture having a uniform composition and properties (same type of matter) Heterogenous mixture - a mixture that is not uniform in composition and properties (different types of matter)

Question 35

Is the air we breathe a pure substance or a mixture?

Answer 35

Mixture

Question 36

Is the air we breathe a homogeneous or heterogeneous mixture?

Answer 36

Homogeneous mixture; when there is smog it becomes a heterogenous mixture

Question 37

What is a physical change in matter?

Answer 37

A change that alters the state or appearance of matter, but not the composition Ex: Chopping wood for a fire into smaller and smaller pieces

Question 38

What are the 6 phase changes of matter?

Answer 38

1. Melting (solid to a liquid) 2. Freezing (liquid to a solid) 3. Vaporization (liquid to a gas) 4. Condensation (gas to a liquid) 5. Deposition (gas to a solid) - water vapor to ice 6. Sublimation (solid to a gas) - dry ice

Question 39

What is a chemical change?

Answer 39

A change that alters the composition; atoms rearrange and create different substances Ex: Iron rusting; exposure to air changes the molecules to have iron attached to oxygen and drastically changes the properties of a compound Ex: Fire burning wood

Question 40

What are physical properties of matter?

Answer 40

Properties displayed by a substance that does not cause a change in composition Ex: Odor, taste, color, appearance, melting point, boiling point

Question 41

What are chemical properties of matter?

Answer 41

Properties displayed by a substance caused by a change in its composition Ex: corrosiveness, flammability, acidity, toxicity