Answer:
D
Explanation: An exothermic change is Because it has heat.
No because they have the same number of protons not neutrons. fine, their mass nos are equal but isotopy is due to different number of neutrons.
Explanation:

Moles of compound =

We have ;
Volume of solution = 600 mL = 0.600 L ( 1 mL = 0.001 L)
Moles of NaOH = n
Molarity of the solution = 3 M

n = 3 M × 0.600 L = 1.800 mol
Mass of 1.800 mole sof NaOH :
1.800 mol × 40 g/mol = 72.0 g
Preparation:
Weight 72.0 grams of sodium hydroxide and add it to the 500 mL of volumetric flask along with some water. Dissolve the all the solute by adding small proportion of water. After the solution becomes clear make the water upto the mark of 500 ml.
Transfer the solution to a bigger beaker and 100 mL of water more to it.
Answer:
Decomposition Reaction
Explanation:
If you are referring to what type of reaction that occurred then the answer would be decomposition reaction.
This is a chemical reaction where one reactant is broken down into two or more products.
REACTANT → PRODUCT
AB → A + B
The products can be two or more elements or two or more compounds, depending on what was decomposed.
Answer:
When writing equation the mass on left side of equation must be equal to the mass on right side. True
Explanation:
The chemical reactions always follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass because total mass is equal on both side of equation.