6. Dentists use a soft, clay-like material to make a filling for a cavity. The filling stays soft under the light of the dentist's lamp, but it hardens when the dentist shines an ultraviolet flashlight on it. Why
does light from the ultraviolet flashlight harden the filling when light from the lamp does not?

There are 6.022, 104 atoms of hg in 1 mole of hg the number of atoms in 45 moles of hg can be found by multiplying 4.5 by 6.022, 102 which is the number of atoms in 4.5 moles of hg, correctly written in scientific notation with the correct number of significant figures? 0 21,109 0 21,100 271, 1024 27.099, 100 mark this and retum save and exit submit

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

The number of moles of a given mass of a substance can be found without knowing its molecular formula or molar mass. true false