I believe it's answer #3. Logically, at least.
You can test #1 through trial and error.
You can experiment #2 also through trial and error.
You cannot test #3 through trial and error, because that would be catastrophic.
You can test #4 through a survey and individual study and data collection.
Answer choice A, B, and C is right about the valence electrons. For answer choice D and E, Would in it be a more of an element kind of choice. whether the element is closer to the left side of the periodic table or not determines the high and low energy.
Answer:
We need 50.6 grams of oxygen
Explanation:
Step 1: Data given
Mass of ethane = 13.6 grams
Molar mass of ethane = 30.07 g/mol
Step 2: The balanced equation
2C2H6 + 7O2 → 4CO2 + 6H2O
Step 3: Calculate moles ethane
Moles ethane = mass ethane / molar mass ethane
Moles ethane = 13.6 grams / 30.07 g/mol
Moles ethane = 0.452 moles
Step 4: Calculate moles oxygen
For 2 moles ethane we need 7 moles O2 to produce 4 moles CO2 and 6 moles H2O
For 0.452 moles ethane we need 3.5*0.452 = 1.582 moles O2
Step 5: Calculate mass O2
Mass O2 = moles O2 * molar mass O2
Mass O2 = 1.582 moles * 32.0 g/mol
Mass O2 = 50.6 grams
We need 50.6 grams of oxygen
The question is incomplete, the complete question is;
Which statement describes a difference between electromagnetic and mechanical waves?
A. Mechanical waves cannot be longitudinal, but electromagnetic waves can.
B. Electromagnetic waves cannot move particles, but mechanical waves can.
C. Electromagnetic waves do not require a medium, but mechanical waves do.
D. Mechanical waves do not transfer energy, but electromagnetic waves do.
Answer:
Electromagnetic waves do not require a medium, but mechanical waves do.
Explanation:
A wave is defined as a disturbance along a medium which transfers energy. Waves may be classified as mechanical waves or electromagnetic waves based on their medium of propagation.
A mechanical wave requires a material medium for propagation. An example of a mechanical wave is sound waves. Sound waves are propagated in air.
Electromagnetic waves do not require a material medium for propagation. They can travel through space. An example of electromagnetic waves is light waves.
