Physical. When you simply desolve something with water, to don't actually change it. This action can be undone.
An example of a chemical reaction is when the cells within completely change. You you burn wood, you can't go back in time and un-burn it. Does that make sense?
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.
Answer: 2 moles
Explanation:
STP is Standard Temperature and Pressure. That means the pressure is 1.00 atm and the temperature is 273K. Since the oxygen is placed in the same container, we can use Ideal Gas Law to figure out what container the CO₂ used.
Ideal Gas Law: PV=nRT
P=1.00 atm
n=moles
R=0.08206 Latm/Kmol
T=273K
CO₂



Since we know that CO₂ has a 44.8 L container, we can use that to find the moles of oxygen.



There are 2 mol of oxygen.
SI unites are based on multiplying or dividing by 10, 100, 1,000, 10,000 (and so on...) depending on the unit you're solving for.
Answer:
The correct answer is - scientific law.
Explanation:
A scientific law is an explanation to a well observed phenomenon of the world which is found true every time tested and universal proven fact, but the reason behind the phenomenon and its existence.
To explain the scientific law there will be various explanation that are called scientific theory, however these theories can not be proved.
Thus, the correct answer is - scientific law.