Answer:
The mass stays the same only volume changes, the volume decreases
Explanation:
The ice shrinks (decreases volume) and becomes more dense. The weight will not (and cannot) change.
Answer:
A Chemical equation is balanced if the reactants side of the chemical reaction has the same number total of atoms of elements as the products side of the chemical equation. While a Chemical equation is unbalanced if the reactants side of the chemical reaction has a different number total of atoms of elements as the products side of the chemical equation
Explanation:
Self explanatory
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:
