Answer:
Periods have consecutive atomic number as they are in a row and groups are vertical meaning they are in a column and groups have similar properties
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.
To answer the question that is: "which factors affect a river's load", we have to understand that all the things mentioned are important. All these options (river's slope, streambed shape and volume of flow) affect the amount of energy that the river has to spend and the way the river spend that energy, so, it is right to mark the alternative <span>d) all of the above.</span>
Answer : Option B) Lead
Explanation : Lead is chemical element which damages<span> the central nervous system, cardiovascular system, reproductive system, hematological system, and kidneys with overexposure as compared to other elements in the given option.</span>