Explain what a compound is and how you can tell one by looking at a chemical formula?

Explanation:

Chemical Compounds are substances that are made up of 2 or more elements that have reacted to each other through a chemical bond to give a different substance to the initial elements.

The chemical formula is an expression used to indicate the molecular composition of a compound. In other words, it indicates by means of symbols the elements that make up the compounds and their proportion.

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

the answer is 1 i believe