Part+1-Physical+&&+Chemical+Properties,

 Physical Property - any property that can be observed or measured without forming a new substance is a physical property.The color of both helium and hydrogen can be observed without touching or changing either one. Therefore color is a physical property. Density is also a phyical property.

a charactistics of a substance that can change without forimg a new substance (e.g, the density of water changes when water turns from a liquid to a gas.)

Chemical Property- Any property that describes how a substance reacts with another substance when forming a new substance is a chemical property. Combustibility is therefore a chemical property. Hydrogen burns in air, so it does have the property of combustibility.

a charactistic of a substance that describes it`s albility to react chemically with other substances, (e.g, whether the substance will burn in air.)  