What is meant by radioactivity?

-high-energy subatomic particles
-disintegration of the nucleus
-unstable atoms
-all of the above

Which statement about covalent bonds is true

A1.5m wire carries a 2 a current when a potential difference of 52 v is applied. what is the resistance of the wire?

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?