Answer:
d. 50 C
Explanation:
In this problem, we have to add 800 ml of water at 20 Celsius to 800 ml of water at 80 Celsius.
According to the 2nd law of thermodynamics, heat transfers from hot to cold temperature.
The quantity of both the different waters is equal so this makes it very easy. All we have to do is find the mean of both the temperatures:
Final temperature = (20 C + 80 C)/2
= 50 Celsius
To calculate the number of sig figs
1. Count ALL nonzero numbers
2. If the zero is between 2 numbers, count it
3. If in a decimal the zero is at the end, count it
4. In a decimal all the zeros before the first nonzero number are placeholders and don't count them
5. In a number greater than zero all zeros AFTER the last nonzero number are placeholders and don't count them.
A - 5
B - 2
C - 3
D - 1
E - 4
Fusion reactions happen in stars
Answer:
A. Materials with a low index of refraction cause light to refract very little.
