I would say A but then again im not too sure so hope that makes it easier to somehow
Answer:
1. 1568 J
2. 0 J
3. 1176 J
Explanation:
PE = mgh
(PE = Potential Energy) = (m = mass)(g = gravitational force which is 9.8)(h = height)
1. (3)(9.8)(20) = 1568 J
2. PE = (3)(9.8)(0) = 0 J
3. (5)(9.8)(24) = 1176 J
Answer: The correct formula is 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here magnesium is having an oxidation state of +2 called as 
cation and bromine 
is an anion with oxidation state of -1. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral .
The cations and anions being oppositely charged attract each other through strong coloumbic forces and form an ionic bond.
The freezing point depression is a colligative property which means that it is proportional to the number of particles dissolved.
The number of particles dissolved depends on the dissociation constant of the solutes, when theyt are ionic substances.
If you have equal concentrations of two solutions on of which is of a ionic compound and the other not, then the ionic soluton will contain more particles (ions) and so its freezing point will decrease more (will be lower at end).
In this way you can compare the freezing points of solutions of KCl, Ch3OH, Ba(OH)2, and CH3COOH, which have the same concentration.
As I explained the solution that produces more ions will exhibit the greates depression of the freezing point, leading to the lowest freezing point.
In this case, Ba(OH)2 will produce 3 iones, while KCl will produce 2, CH3OH will not dissociate into ions, and CH3COOH will have a low dissociation constant.
Answer: Then, you can predict that Ba(OH)2 solution has the lowest freezing point.
Answer:
C. He shot tiny alpha particles through a piece of gold foil.
Explanation:
In the year 1911, Ernest Rutherford performed the gold foil experiment which gave a deeper perspective to the structure of an atom.
He simply collided a thin gold foil with an alpha particle which he generated from a radioactive source. He discovered that most of the alpha particles passed through the thin gold foil but a few were deflected back. His discovery led to the proposition of the nuclear model of the atom.
