As you can search and read the definition of a scientific experiment is the process of testing and finding the truth through this scientific method. Thus, all items are considered scientific experiment except for item "c" Ask her coworkers which solution they thick is better.
The pH level changed to 1.34 and the combination of the both made the mixture less acidic
the pH is 1.84, mixture had less acid and there is alot more water molecules in the mixture
the pH level is 2.13 ,, again less acidic and the water molecules has increased to 3,28 x10(25)
<u>Answer:</u> The time taken by the reaction is 84.5 seconds
<u>Explanation:</u>
The equation used to calculate half life for first order kinetics:

where,
= half-life of the reaction = 9.0 s
k = rate constant = ?
Putting values in above equation, we get:

Rate law expression for first order kinetics is given by the equation:
......(1)
where,
k = rate constant = 
t = time taken for decay process = 50.7 sec
= initial amount of the reactant = ?
[A] = amount left after decay process = 0.0741 M
Putting values in equation 1, we get:
![0.077=\frac{2.303}{50.7}\log\frac{[A_o]}{0.0741}](https://tex.z-dn.net/?f=0.077%3D%5Cfrac%7B2.303%7D%7B50.7%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B0.0741%7D)
![[A_o]=3.67M](https://tex.z-dn.net/?f=%5BA_o%5D%3D3.67M)
Now, calculating the time taken by using equation 1:
![[A]=0.0055M](https://tex.z-dn.net/?f=%5BA%5D%3D0.0055M)

![[A_o]=3.67M](https://tex.z-dn.net/?f=%5BA_o%5D%3D3.67M)
Putting values in equation 1, we get:

Hence, the time taken by the reaction is 84.5 seconds
Answer:
a) 
b) 
c) 
d) 
Explanation:
For neutral atoms:
Atomic Number (Z)= number of protons = number of electrons
Mass number (A) = number of protons + number of neutrons
For ions with positive net charge:
Number of protons = Z + net charge
For ions with negative net charge:
Number of protons= Z - net charge
a) A = 71, Charge = +3
Number of electrons = 28
Number of protons = 28 +3 =31

b) A = 35, Z = 45+35=80, Charge = -1
Number of protons =35
Number of neutrons = 45
Number of electrons = 36
Charge = Number of protons- Number of electrons =35-36 = -1

c) Charge = +4
Number of electrons = 86
Number of protons = Z = 86+4 = 90
mass number = A = 90+142 = 232

d) Charge = +2
Atomic number = Number of protons = Z = 38
mass number = A = 87

Answer:
single displacement
Explanation:
the Fe was switched out with the C. they are the only ones that switched, making it a single displacement