During a lab investigation a scientist heats a solid substance. The scientist observes that the solid
has two different melting points. The scientist
is able to separate the two resulting liquids.
Which statement best classifies the original solid
substance?
A.
It was an atom.
B.
It was a mixture.
0.
It was an element.
D. It was a compound.

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

you need to have a picture of the atom that way we can answer it