Many metals pack in cubic unit cells. the density of a metal and length of the unit cell can be used to determine the type for packing. for example, polonium has a density of 9.19 g/cm3 and a unit cell side length a of 3.37 å. (1 å = 1 10-8 cm.) (a) how many polonium atoms are in exactly 1 cm3? atoms (b) how many unit cells are in exactly 1 cm3? unit cells (c) how many polonium atoms are there per unit cell?

Start an single atom tab. observe the decay of polonium-211. after each decay, press the reset nucleus button to watch the process again. write a description of alpha decay for po-211

Which explanation is true about what happens to a ray of light when it strikes a mirror? a. a light ray is transmitted toward a mirror at a certain angle. the light ray is then reflected by the mirror at an equal angle but in the opposite direction of the transmitted ray. b. an incident ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then reflected at an angle equal to the angle of incidence but on the opposite side of the perpendicular line. c. a reflecting ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then refracted at an angle equal to the angle of the reflecting ray and on the same side of the perpendicular line. d. an incident ray strikes a mirror at an angle with a line parallel to the mirror. the light ray is then transmitted at an angle equal to the angle of incidence but on the opposite side of the parallel line. you so much! : -d take the time to try and answer correctly.

Predict the reactants of this chemical reaction. that is, fill in the left side of the chemical equation. be sure the equation you submit is balanced. (you can edit both sides of the equation to balance it, if you need to.) note: you are writing the molecular, and not the net ionic equation. > cacl2(aq) + h20(l)