A reaction vessel that is completely sealed and the Earth would be my answers. This is because the matter inside of these systems is not exchanged anywhere but inside itself. (the glass flask could count, but the not insulated thing might be why it doesn’t count)
Inherited it from his grandfather
The hydrogen ion concentration, [H ], in the solution of phenol red solution of pH 11.20 is 6.3 X 
moles/litre.
Explanation:
Data given:
basic solution of phenol red is given as it has pH of 11.2
hydrogen ion concentration = ?
the hydrogen ion concentration is calculated by using the following formula:
pH = -
[
]
Rearranging the equation:
[] = 
Putting the values in the above equation:
[] = 
[] = 6.3 X moles/litre
The hydrogen ion concentration is very small and the solution of phenol red is basic in nature. The pH of 11.2 also indicates that solution is basic and teh color of the solution is bright pink.
Answer:
The answer is the same as 9.11x10-31kg which is the mass of an electron,
Explanation:
The mass of an electron expressed in standard form is 9.11x10-31, which is the same thing as 0.000000000000000000000000000000911, while the former looks compact and easier to understand, the latter is clumsy,
The concept of three significant figures mean, three non-zero figures, in other words, provide your answer in an approximate form using three figures apart from zero, so you would try to express your answer in such a way that the first digit in your answer is not zero, in this case, its a "nine" - "9", and the other two significant figures are "1" and "1".
It is a compound machine i think, tell me if its right!
