Which option is an example of a physical property? question options: reactivity ph density rusting ability

Which uses electromagnetic radiation to discover the properties and composition of bodies in space? space probe space station space shuttle space observatory

The answer for #3 is c but i don't know why

What type of energy do chemical bonds have? what type of energy is it converted to during chemical reactions? question 15 options: chemical bonds have kinetic energy, which is converted to potential energy during chemical reactions. chemical bonds have electric energy, which is converted to potential energy during chemical reactions. chemical bonds have heat energy, which is converted to kinetic energy during chemical reactions. chemical bonds have potential energy, which is converted to heat energy during chemical reactions.