Activation energy in reaction is used to: A- Overcome repulsion force between colliding molecules
B- Breaking bonds
C- Merge Valence electrons
D- All of them

D — All of them

Explanation:

The activation energy in a reaction is the minimum amount of energy required for a chemical reaction to take place. Since all the options are processes in a chemical reaction, D should be the answer.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance