Answer:
C. Magnetization of iron
Explanation:
This is a chemical change and cannot be undone by physical means therefore it isn't a physical change
Answer:
Complex formation
Explanation:
At first sight, one may think that a reaction between calcium oxalate and platinum metal is impossible considering the relative positions of the two metals in the electrochemical series.
However, in solution, calcium oxalate dissociates into calcium and oxalate ions. When platinum is added to this solution, a complex is formed between the platinum ions and the oxalate ions. Hence a reaction occurs for this reason.
Answer : The mass of the water molecule is 4.5 times greater than the mass of the helium atom.
Explanation :
Assumption : The number of water molecules is equal to the number of helium atoms
Given : The mass of water = 4.5 × The mass of helium ........(1)
The mass of Water = Mass of 1 water molecule × Number of water molecule
The mass of Helium = Mass of 1 helium atom × Number of helium atom
Now these two masses expression put in the equation (1), we get
Mass of 1 water molecule × Number of water molecule = 4.5 × Mass of 1 helium atom × Number of helium atom
As per assumption, the number of water molecules is equal to the number of helium atoms. The relation between the mass of water molecule and the mass of helium atom is,
Mass of water molecule = 4.5 × Mass of helium atom
Therefore, the mass of the water molecule is 4.5 times greater than the mass of the helium atom.
True, because most chemical reactions have more moles but not really.
Also that they decompose better. "not really"
Colligative properties depend on the amount of solute dissolved in a solvent. These set of properties do not depend on the type of species present. These properties include freezing point depression, boiling point elevation, osmotic pressure and vapor pressure lowering.
