Potassium and iodine have formed a bond. prior to this the potassium gave up an electron. it became a positive ion neutral atom negative ion shared ion

it is positive ion i did some research and its positive ion

Explanation:

i look it up online and i'll tell you

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