You can look at magnesium, it can react with oxygen to form oxides. (chemical) it is malleable and a solid at room temperature. (physical)
to measure its density, the mass and volume can be worked out and from this density too. look up the equation, it is quite easy :)
physical changes -- it can be melted, and oxidized <span />
-- the applicant's previous experience at similar jobs;
-- the color of the applicant's hair;
-- the applicant's grammar and vocabulary;
-- where the applicant went to school;
-- the shirt the applicant wears to the job interview;
-- the applicant's favorite football team;
-- the applicant's self-confidence;
The motion of the object will be increased due to the air decreased resistance.
I'm not sure if nuclear energy is turned into thermal energy using this method, but it definitely makes energy; the reactor fissions a uranium-235 isotope into multiple pieces and controls the energy. The reactor core sits inside a steel pressure vessel, so that water around it remains liquid even at the operating temperature of over 320°C. Steam is formed either above the reactor core or in separate pressure vessels, and this drives the turbine to produce electricity. The steam is then condensed and the water recycled.