the nuclei of some isotopes are radioactive which one of the following statements could apply to a radioactive nucleus

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.

Which statement describes the phase change that occurs when dry ice is placed in an open container at room temperature?

What is the wavelength of a wave with a velocity of 50 m/s and a frequency of 5hz a 250 m b 0.1 m c 10m d 0.01 m