Answer:
V₁ = 10 mL
Explanation:
Given data:
Initial volume of HCl = ?
Initial molarity = 3.0 M
Final molarity = 0.10 M
Final volume = 300.0 mL
Solution:
Formula:
M₁V₁ = M₂V₂
M₁ = Initial molarity
V₁ = Initial volume of HCl
M₂ =Final molarity
V₂ = Final volume
Now we will put the values.
3.0 M ×V₁ = 0.10 M×300.0 mL
3.0 M ×V₁ = 30 M.mL
V₁ = 30 M.mL /3.0 M
V₁ = 10 mL
I think the answer is B...
I am not sure
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:

Answer:
1. Molecular solids are usually excellent conductors of electric current.
Explanation:
Molecular solids are actually insulators (prevent electricity).