If a substance is changing from a vapor to a liquid, like steam on a mirror, it is said to be

a. condensing
b. crystallized
c. volatile
d. changing pigmentation

What semimetal can form four single covalent bonds.

Can someone me with questions 15 to 17 plz.

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.