Answer:
Systematic errors.
Explanation:
The density of the aluminium was calculated by a human and this is not natural but can be due to errors in the calibration of the scale for measuring the weight or taking readings from the measuring cylinder.
Random errors are natural errors. Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. Systematic errors are due to imprecision or problems with instruments.
energy extracted out of liquids an atoms are left to come closer arrange themselves shorter distance and then they solidify
Liquids state than in the solid state because when it is solid the particals cant move as much than in the liquid state
Answer:

Explanation:
= Mg ion = 
= F ion = 
q = Charge of electron = 
r = Distance between ions = 
k = Coulomb constant = 
Electrical force is given by
![F=-\dfrac{kq_1q_2}{r^2}\\\Rightarrow F=-\dfrac{8.99\times 10^9\times 2\times 1.6\times 10^{-19}\times -1\times 1.6\times 10^{-19}}{[(0.072+0.133)\times 10^{-9}]^2}\\\Rightarrow F=1.09527\times 10^{-8}\ N](https://tex.z-dn.net/?f=F%3D-%5Cdfrac%7Bkq_1q_2%7D%7Br%5E2%7D%5C%5C%5CRightarrow%20F%3D-%5Cdfrac%7B8.99%5Ctimes%2010%5E9%5Ctimes%202%5Ctimes%201.6%5Ctimes%2010%5E%7B-19%7D%5Ctimes%20-1%5Ctimes%201.6%5Ctimes%2010%5E%7B-19%7D%7D%7B%5B%280.072%2B0.133%29%5Ctimes%2010%5E%7B-9%7D%5D%5E2%7D%5C%5C%5CRightarrow%20F%3D1.09527%5Ctimes%2010%5E%7B-8%7D%5C%20N)
The attractive force is 