Chemical reactions occur when molecules or atoms collide so that the bonds between atoms break and new bonds form. breaking the bonds of the reactants requires energy; whereas, bond formation releases energy. select the statements regarding energy changes during a reaction that are true.

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

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.