Answer:Yes, water indeed expands when it changes form from liquid to solid. And this is because water has a property called “hydrogen bonds”, and these bonds occur between each water molecule. But when water is in a liquid form these hydrogen bonds break more easily and occur less frequently. When the temperature drops the kinetic energy also drops, which in turn makes hydrogen bonds form more frequently. So the water molecules form a lattice, which is less dense than regular liquid water.
Explanation:
Answer:
Velocity of a proton,
Explanation:
It is given that,
Potential difference, 
Let v is the velocity of a proton that has been accelerated by a potential difference of 15 kV.
Using the conservation of energy as :

q is the charge of proton
m is the mass of proton




or

So, the velocity of a proton is
. Hence, this is the required solution.
Answer:
L = 8694 Kg.m²/s
Explanation:
r = 270 ĵ m
v = 14 î m/s
m = 2.3 kg
θ = 90º
L = ?
We can apply the equation
L = m*v*r*Sin θ
L = (2.3 kg)*(14 m/s)*(270 m)*Sin 90º = 8694 Kg.m²/s
The object that goes through chemical change, changes completely to where you can not change it back to its original form. Physical change you can undo