"Hornblende is a jet black mineral commonly found in igneous rocks and has the formula Ca2Fe3Si8022(OH)2 explain how to figure out the ionic charge of the Fe and Si ions and what their charges are."

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

indium, and thallium have three electrons i think

its first and third is your answer i did the qustion the fourth isnt right