The correct answer is Be+
That is because it lost a single electron but still has the same number of protons, and thus the effective charge attracting each electron is greater, which in turn makes the radius even smaller
When naming an ionic compound, write the name of the cation, which is the metal first. Then, write the name of the anion, which is the nonmetal. However, you remove the last 2-3 letters and replace suffixes.
1. RbF --> Rubidium Fluoride
Change fluorine to fluoride
2. CuO --> Copper (II) Oxide
Change oxygen to oxide. Oxide has a charge of -2. Since no subscripts are written, it means they have the same opposite charge. So, we use Copper (II).
<span>3. (NH</span>₄<span>)</span>₂<span>C</span>₂<span>O</span>₄ ---> Ammonium Oxalate
NH₄ is ammonia, but we change it to ammonium for polyatomic ions.
If the cube is 3 cm on each side, then it has a volume of 27 cm^3 (3 x 3 x 3). Density is mass divided by volume, so its density is 72.9/27 = 2.7 g/cm^3.
<span>Going by the density, the cube is made of Aluminium - density is a fairly unique quantity</span>
I think that the answer is (D)... I hope this helped
