Answer:
A scientific question is basically a question that can lead to a hypothesis to help us figure out the observation in science. I hope this helps you
Answer: a) 
b) 
c) 
d) 
Explanation:
General representation of an element is given as:_Z^A\textrm{X}
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
It is characteristic of a particular element.
Atomic number = Number of electrons = Number of proton
a) Z 74, A 186: 
b) Z 80, A 201: 
c) Z 34, A 76: 
d) Z 94, A 239.: 
Answer:
4.22
Explanation:
pH stands for potential hydrogen. The letter “p” denotes potential and the letter “H” denotes hydrogen.
pH helps to find the acidity or alkalinity of an aqueous solution.
The number of hydrogen ions (protons) present in a solution is determined by the pH scale.
A pH greater than 7 makes the water more alkaline and a pH less than 7 makes the water more acidic.
![pH=-\log [H^+]=-\log [0.00006]=4.22](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%3D-%5Clog%20%5B0.00006%5D%3D4.22)
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.
Answer:
228 mL
Explanation:
M1*V1 = M2*V2
M1 = 6.58 M
V1 = ?
M2 = 3.00 M
V2 = 500 mL
V1 = M2*V2/M1 = 3.00M*500.mL/6.58 M = 228 mL