Explain why neither liquids nor gases have a shape

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?

At a certain temperature the rate of this reaction is first order in hi with a rate constant of : 0.0632s2hig=h2g+i2g suppose a vessel contains hi at a concentration of 1.28m . calculate how long it takes for the concentration of hi to decrease to 17.0% of its initial value. you may assume no other reaction is important. round your answer to 2 significant digits.

The point along a planet's orbit where it is closest to the sun is called the