3I₂ + 2Al → 2AlI₃
m(I₂)=3M(I₂)m(Al)/{2M(Al)}
m(I₂)=3*253.8*20.4/{2*27.0}=287.64 g
Answer: for 3. I would say it means that the amplitude is greater because if a sound is louder that means the amplitude is larger, same with the light.So that would mean the softer the sound the smaller the amplitude same with the dim of the light so for 4. It would be the amplitude is smaller. Hope this helps! :) ( if you have any questions feel free to ask)
Answer:
C. Chemical change
Explanation:
A physical change is where something is changed but it doesnt affect the build up of the chemical. For example, if you broke sticks and threw them on the ground, that would be a physical change because the change is happening to the physical being of the object and not its chemical buildup. However, if you lit those sticks on fire, that would be considered a chemical change because you end up with two substances, ash and the remnants of the stick. A nuclear reaction would result in something blowing up so its not that. And a physical property is like what it looks like or how it smells. Hope I helped you!
Answer: The mass of the sample will be 1417.7 grams.
Explanation:
We are given:
This means that 1 mole of NaCl has an enthalpy of fusion of 30.2 kJ
1 mole of NaCl has a mass of 58.44 grams.
So, 30.2 kJ of heat is require for a mass 58.44 grams of NaCl
So, 732.6 kJ of heat will be required for = 
= 1417.65 grams of NaCl.
Hence, the mass of NaCl sample will be 1417.7 grams.
Answer:
This question is incomplete
Explanation:
This question is incomplete because the result of the described experiment would have better determined the type of scientific explanation to profer. However, the type of material that will preserve the relative hotness or temperature of the hot coffee for the longest time will be a material than can resist heat transfer. These materials tend to keep hot substances hot by not allowing the heat of the coffee to be conducted or pass through it. These materials are mostly insulators or made by placing an insulator between two heat conductors.
Generally, heat is usually transferred from a region of higher concentration to a region of lower concentration, hence when the heat is denied of this transfer, the heat will remain trapped in the "heat-donor" substance (in this case the hot coffee). Thus, the material chosen (A, B or C) will be the material that resists heat transfer the most based on the explanation above.
