Midterm

Question 1

Extrinsic physical properties ___________.

Answer 1

Depend on the amount of the matter in the sample

Question 2

Intrinsic Physical properties _________.

Answer 2

Depend upon the nature of the matter in the sample.

Question 3

Are melting solids and/or boiling liquids physical or chemical changes?

Answer 3

Physical because it is a phase change and no new substance is created.

Question 4

Is making a solution by dissolving salt into water a physical or chemical change?

Answer 4

Physical because once the water had evaporated, the salt remains. (Evaporation being a physical mean of separation)

Question 5

Example of physical change and explain why.

Answer 5

Ice melting because it is a phase change and no new substance is created.

Question 6

Example of chemical change and explain why

Answer 6

Burning wood because the wood reacts with the oxygen through combustion and creates heat, light, and new substances.

Question 7

Example of nuclear change and explain why

Answer 7

Fusion because this is smashing two atoms together to create another atom, which is a change in at least proton numbers in the nucleus.

Question 8

Define solid and give an example

Answer 8

Has a definite shape and volume.

Graphite

Question 9

Define liquid and give an example

Answer 9

Has a definite volume, but an indefinite shape. Takes shape of the bottom of container.
Water

Question 10

Define gas and give an example

Answer 10

Has an indefinite shape and volume. Will fill a sealed container.
Air

Question 11

Define plasma and give an example

Answer 11

Ionized gas of positive ions and free electrons at low pressure or super heated.
Neon gas in neon signs

Question 12

What is (aq)?

Answer 12

Aqueous solution- a solution where the solvent it water.
Ex: Na+(aq)+Cl-(aq) (salt water)
Not a phase of matter, but a specific type of homogeneous mixture

Question 13

Difference between separating mixtures and separating compounds.

Answer 13

Mixtures must be separated with physical means.

Compounds must be separated with chemical means.

Question 14

Explain a technique for separating a mixture

Answer 14

Filtration is a method used to separate larger particles in a mixture from smaller ones. Larger particles remain as the residue and the smaller ones are the filtrate.

Question 15

Explain a technique for separating a compound

Answer 15

Electrolysis is a chemical reaction induced by electricity used to separate the elements of a compound. (Ex: H2O into H2 and O2)

Question 16

Explain the law of conservation o mass wit an example.

Answer 16

The burning of a candle results in the oxygen gas combining with the carbon and hydrogen in the wax to create carbon dioxide, carbon monoxide, and water vapor. This means the mass of the wax and the oxygen must equal that of the produced CO2, H2O, and CO.

Question 17

Explain precision and accuracy with an example. Which does prevent error calculate?

Answer 17

In archery, precision is when all the arrows are close together, but not near the bulls eye. Accuracy would be one bullseye, and other scattered shots. Precision and accuracy would be several bullseyes or very close to it.
Prevent error calculates accuracy. (Accepted-Experimental)/Accepted

Question 18

Word and symbol for the base SI unit of mass

Answer 18

Kilograms

kg

Question 19

Word and symbol for the base SI unit of amount of a substance

Answer 19

Mole

mol

Question 20

Word and symbol for the base SI unit of length

Answer 20

Meter

m

Question 21

Word and symbol for the base SI unit of time

Answer 21

Seconds

s

Question 22

Word and symbol for the base SI unit of temperature

Answer 22

Kelvin

K

Question 23

Word and symbol for the derived SI unit of volume.

Answer 23

Liters
L
Centimeters cubed
cm^3

Question 24

Word and symbol for the derived SI unit of density

Answer 24

D=m/v
Grams/milliliters
g/mL
Kilograms/Liters
kg/L

Question 25

Word and symbol for the derived SI unit of pressure

Answer 25

Pascal
Pa
Torr
torr

Question 26

Symbol and numerical value of milli-

Answer 26

m
1/1000
0.001
1x10^-3

Question 27

Symbol and numerical value of kilo-

Answer 27

k

1000

Question 28

Symbol and numerical value of centi-

Answer 28

c
100
1/100
0.01

Question 29

Convert °C to K and K to °C

Answer 29

°C + 273.15 = K

K - 273.15 = °C

Question 30

List five things we know that Dalton didn’t due to modern atomic theory.

Answer 30

Isotopes exist, atoms have nuclei, there are subatomic particles (proton, neutron, electron), existence of electron energy levels, orbitals, and clouds, and nuclear reactions.

Question 31

Discoverer and experiment name for atoms

Answer 31

John Dalton
Law of conservation of mass
Law of definite proportions
Law of multiple proportions

Question 32

Discoverer and experiment name for the nucleus

Answer 32

Ernest Ruthford

Gold foil experiment

Question 33

Discoverer and experiment name for electron energy levels

Answer 33

Neil Bhor

Bhor model/planetary model/orbitals

Question 34

Discoverer and experiment name for protons

Answer 34

Eugene Goldstein

Cathode ray tubes (canal rays)

Question 35

Discoverer and experiment name for electrons

Answer 35

J. J. Thompson

Cathode ray tube (cathode rays)

Question 36

Discoverer and experiment name for neutron

Answer 36

James Chadwick

Beryllium foil bombarded with alpha particles

Question 37

Draw 5 atomic models to show development of atomic structure.
I tried, so don’t judge. 😅

Answer 37

“Billiard ball”
🎱 solid sphere
“Plum pudding”
🍪
Positive sphere with negative particles in it
Ruthford model
⚛️
Positive nucleus with electrons circling around
“Planetary model”
🎯
A positive nucleus with orbital power levels for electrons around it.
Electron cloud
📀
Positive nucleus (with neutrons as well as protons) surrounded by a sphere shaped cloud of electrons.

Question 38

List the three subatomic particles, their symbols, relative mass and charge, and positions in atom

Answer 38

Name Symbol Relative Relative Position
Charge Mass In atom
Neutron n° 0 1 Nucleus
Proton p^+ +1 1 Nucleus
Electron e^- -1 0 Electron cloud

Question 39

Calculate weighted average

Or average atomic mass

Answer 39

(Atomic mass number x Percent abundance) + (Atomic mass number x Percent abundance)= Average Mass number

Add more (Atomic mass number x Percent abundance) to equal number of isotopes. Also, Average Atomic Mass should be very close to that on the periodic table.

Question 40

ALSO REVIEW:

Answer 40

Lab safety
Physical, chemical, and nuclear properties
Physical, chemical, and nuclear changes
Compound vs. Mixture
Sigfigs
Scientific notation
Dimensional analysis
Labs