Which of the following observations indicates that an atom has neutrons? A.) Some uncharged particles are scattered by a beryllium atom when it hits a gold foil.

B.) Some uncharged particles bounce back from a gold foil when it is bombarded with alpha particles.

C.) A radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms.

D.) A radiation which attracts electrons is produced when a beryllium atom is bombarded with alpha particles.

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 correct answer is:

a. formation of precipitation