Level 4: You are attempting to identify an unknown substance. Use the table to answer the questions below.
Substance
Formula Mass,
Color
Physical
State
Density Boiling
. (g/cm) Point,'c
Methane
CH
16.0
Gas
Colorless
0.423
-161.5
Ammonia
NH
17.0
Gas
Colorless
0.70
-33
Unknown
???
???
???
???
PP?
???
Propane
CH
44.1
Gas
Colorless
0.493
-49.1
Bromine
Bry
159.8
Liquid
Red
4.04
58.8
Lithium
Li
6.94
Solid
0.534
1342
Silvery,
white
metal
Magnesium Mg
24.3
Solid
1.74
1090
Silver,
white
metal
Your goal is to identify what substance the unknown is. List 5 testa/observations you
could use to determine what the unknown substance in the chart is using your
knowledge of chemical and physical properties.
Test/Observations #1:
Test/Observations #2:
Test/Observations #3:
Test/Observations #4:
Test/Observations #5:

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

hope i !