The half-life of Radium- 226 is 1590 years. If a sample contains 500 mg , how many mg will remain after 3000 years?

Based on your worksheet results, please match the following: The electron group geometry of NH 3 is The electron group geometry of BF 3 is [Choose ] The electron group geometry of \( \mathrm{PF5} \) is [Choose ] [Choose ] electron group geometry of SF4 is geometry of PF 3 is [Choose ]

Please select the molecule(s) that 1) its molecular shape is different from its electron group shape, and/or 2) the central bonds are not identical. NH3 BF3 PFF PF3

Please select the molecule(s) with double bond(s) from the following. \( \mathrm{CCl}^{2} \) CHCl 3 CO 3 H 2 O None

There are different types of food coloring available in most grocery stores- one that is water-based, and one that is oil-based. The oil-based food coloring works best in chocolates, in fry-oil to color fried foods, and in food with high butter contents. Based off of this information and knowing that substances of like polarity mix readily with one another, which food coloring is more polar (water-based or oil-based)? Which food coloring is less polar (or even nonpolar)? Water-based [Choose ]

Please select the molecule(s) with resonance structures from the following. CCl 4 CHCl 3 SO 3 H 2 O None