24. A, natural ph scale for it not to be acidic is 7-8
25. A, not sure about this one
26. A, looked it up
27. A, because it has to be shaken up to make the mixture appear and taste more combined.
28. D, i just guessed
29. D, that answer is stupid so it is the answer because it said not a property
30. A, looked it up
Answer:
n=2.053
Explanation:
We will use Snell's Law defined as:
Where n values are indexes of refraction and 
values are the angles in each medium. For vacuum, the index of refraction in n=1. With this we have enough information to state:
Solving for 
yields:
Remember to use degrees for trigonometric functions instead of radians!
Answer:
Mass = 64,870,000,000 kilograms
Explanation:
Given the following data;
Density = 998 kg/m³
Volume = 6,500,000 m³
To find the mass of water in the reservoir;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
Density = mass/volume
Making mass the subject of formula, we have;
Mass = density * volume
Mass = 998 * 6,500,000
Mass = 64,870,000,000 kilograms
<h2>
Answer:</h2>
-310J
<h2>
Explanation:</h2>
The change in internal energy (ΔE) of a system is the sum of the heat (Q) and work (W) done on or by the system. i.e
ΔE = Q + W ----------------------(i)
If heat is released by the system, Q is negative. Else it is positive.
If work is done on the system, W is positive. Else it is negative.
<em>In this case, the system is the balloon and;</em>
Q = -0.659kJ = -695J [Q is negative because heat is removed from the system(balloon)]
W = +385J [W is positive because work is done on the system (balloon)]
<em>Substitute these values into equation (i) as follows;</em>
ΔE = -695 + 385
ΔE = -310J
Therefore, the change in internal energy is -310J
<em>PS: The negative value indicates that the system(balloon) has lost energy to its surrounding, thereby making the process exothermic.</em>
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