Answer:
M
Explanation:
Concentration of ![Cu^{2+} = [Cu(NO_3)_2]](https://tex.z-dn.net/?f=Cu%5E%7B2%2B%7D%20%3D%20%5BCu%28NO_3%29_2%5D)
= 0.020 M
Constructing an ICE table;we have:
![Cu^{2+}+4NH_3_{aq} \rightleftharpoons [Cu(NH_3)_4]^{2+}_{(aq)}](https://tex.z-dn.net/?f=Cu%5E%7B2%2B%7D%2B4NH_3_%7Baq%7D%20%5Crightleftharpoons%20%5BCu%28NH_3%29_4%5D%5E%7B2%2B%7D_%7B%28aq%29%7D)
Initial (M) 0.020 0.40 0
Change (M) - x - 4 x x
Equilibrium (M) 0.020 -x 0.40 - 4 x x
Given that: 
![K_f } = \frac{[Cu(NH_3)_4]^{2+}}{[Cu^{2+}][NH_3]^4}](https://tex.z-dn.net/?f=K_f%20%7D%20%3D%20%5Cfrac%7B%5BCu%28NH_3%29_4%5D%5E%7B2%2B%7D%7D%7B%5BCu%5E%7B2%2B%7D%5D%5BNH_3%5D%5E4%7D)
Since x is so small; 0.40 -4x = 0.40
Then:
M
Answer: you will change the atom from one element to a different element. Sometimes, when you add a proton to an element, the element will become radioactive. If you change the number of neutrons in an atom, you get an isotope of the same element.
Explanation:
Answer:
120,180,90.
Explanation:
PF3Br2 has a trigonal bypiramidal geometry. The three atoms of F will be arranged around the P atom in the same plane and each F-P-F bond will have an angle of 120 degrees. There will be only one Br atom above and beneath the P atom so the bond angle for Br-P-Br will be 180 degrees. Finally, the F−P−Br bond angle will be at 90 degrees.
Answer:
Kinetic energy: 
Velocity: 
Explanation:
From the equations of the photo-electric effect,
We know:
Where,
1.
is the Planck's constant which is 
2.
are the frequency of light emitted and threshold frequencies respectively.
3.
is the kinetic energy of the electrons emitted.
By fact, we come to know that the threshold frequency of Zn is 300nm
And also 
Where ,
1. 
is the speed of light 
2.
is the wavelength.
Thus,
Now to find velocity:
