Answer:
No
Explanation:
The same amount of matter is present before and after chemical and physical changes. Matter cannot be created or destroyed
The testable question which will provide evidence that elements in the same group have similar properties is valency
<h3>What is the valency?</h3>
In essence, how many electrons are present in their outermost shell.
Valency and Groups in the periodic table, elements are arranged in order of their atomic numbers and hence, the periodic table is a systematic arrangement of elements in an array of vertical columns called Groups and horizontal arrays called Periods.
which of the following testable questions will provide evidence that elements in the same group have similar properties A. Valency B. Orbit C. Group D. Period
Since, the reactive capacities of elements is dependent on the number of electrons on its outermost shell, we can conclude on this note that, Elements in the same group have similar properties.
Learn more on Groups and Valency:
brainly.com/question/1645905
Answer:
a) 
b) entropy of the sistem equal to a), entropy of the universe grater than a).
Explanation:
a) The change of entropy for a reversible process:


The energy balance:
![\delta U=[tex]\delta Q- \delta W](https://tex.z-dn.net/?f=%5Cdelta%20U%3D%5Btex%5D%5Cdelta%20Q-%20%5Cdelta%20W)
If the process is isothermical the U doesn't change:
![0=[tex]\delta Q- \delta W](https://tex.z-dn.net/?f=0%3D%5Btex%5D%5Cdelta%20Q-%20%5Cdelta%20W)


The work:

If it is an ideal gas:


Solving:

Replacing:


Given that it's a compression: V2<V1 and ln(V2/V1)<0. So:

b) The entropy change of the sistem will be equal to the calculated in a), but the change of entropy of the universe will be 0 in a) (reversible process) and in b) has to be positive given that it is an irreversible process.
Hey there!
To calculate the percent by mass of the Ca(NO₃)₂ we need to find the total mass first by adding.
896.92 + 22.63 = 919.55
In total, the solution is 919.55 grams.
To find the percent of Ca(NO₃)₂ in the solution, divide the mass of Ca(NO₃)₂ by the total mass and multiply by 100.
22.63 ÷ 919.55 = 0.0246
0.0246 x 100 = 2.46
Ca(NO₃)₂ makes up 2.46% of the solution.
Hope this helps!
Answer:
Chemistry is the scientific study of the structure of substances, how they react when combined and how they behave under different situations.