The option that distinguishes a nuclear reaction from a chemical reaction is D. there is a change in the nucleus.
During a nuclear reaction, two light nuclei combine in order to create a new, heavier one which is different than those two original ones and has additional particles that it didn't have originally. This is what makes the difference between these two reactions.
Answer: The volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Explanation:
According to ideal gas equation:

P = pressure of gas = 1 atm (at STP)
V = Volume of gas = ?
n = number of moles = 0.684
R = gas constant = 
T =temperature =
(at STP)



Thus the volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Answer:
2.17
Explanation:
To calculate pH using the hygrogen ion concentration we must use the following formula:
- log (H+) = pH
All we have to do now is plug in our hygrogen ion concentration and put it in our calculator.
- log (6.8 × 10⁻³) = 2.17
Don't forget proper figures for pH!
Answer:
18 km
Explanation:
To know the distance, you need to be clear in the concept of distance.
According to the physics, the distance is a measurement that refers to the fact of how much an object has move from one point to another.
In this case, we have a person named Steve and he's walking through several points.
To calculate the distance that he moved, you just need to sum all the values of distance. In this case, it's not neccesary to do calculations regarding the components of the x or y axis, because we are not talking about displacement, where it actually counts. But in this case, we just need all the covered distance that Steven walked since the beggining.
So, no more talk, let's do calculations:
D = 5 + 2 + 9 + 2 = 18 km
So the final answer would be:
<h2>
Distance = 18 km</h2>
Hope this helps