Answer:
43.89 min
Explanation:
Given that:-
The speed of light = 
The distance = 
The conversion of distance in km to distance into m is shown below as:-
1 km = 1000 m
So,
Distance = 
The relation between speed distance and time is shown below as:-
Thus,
Time = 2633.33 seconds
Also, 1 s = 1/60 min
So,
Time=
Answer:
The mole fraction of ethanol is 0.6. A 10 mL volumetric pipette must be used for to measure the 10 mL of ethanol. The vessel should be clean and purged.
Explanation:
For calculating mole fraction of ethanol, the amount of moles ethanol must be calculated. Using ethanol density (0.778 g/mL), 10 mL of ethanol equals to 7.89 g of ethanol and in turn 0.17 moles of ethanol. The same way for calculate the amount of water moles (ethanol density=0.997 g/mL). 2 mL of water correspond to 0.11. The total moles are: 0.17+0.11=0.28. Mole fraction alcohol is: 0.17/0.28=0.6
Both of them have high electronegativity. Hence they both tend to gain electrons to gain stability.
I'm not sure about part 1, you may need to google it, but part two is 11 protons, 11 electrons and 12 neutrons. You can find protons and electrons by just looking at the atomic number, and you can find neutrons by subtracting the atomic number from the atomic mass.
The data gotten from ice cores could scientists tell the about future climate change.
