Answer:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
Explanation:
What is the percent composition by mass of oxygen in magnesium oxide, MgO?
Answer: 39.7 percent
Answer:
It becomes a positive ion and its radius decreases
Explanation:
As per the Octet rule, Barium has 2 electrons in its outermost shell. When it loses the two electron it gains two positive charge i.e Ba2+. As the barium loses the two electron from its outermost shell, the outermost shell becomes vacant and thus is no more considered as a part of atomic geometry of the barium atom and since the outermost shell is considered negligible the radius of barium atom reduces automatically.
Above it says the molecular weights are
NH3- 17g/mol and SF6-146 g/mol
Well 1 mole of SF6 is 146.048 grams (i added hte atomic masses of each element). So then the number of moles in 0.85 grams would be 0.00582000438 moles.
<span><span><span>= 1mole / </span><span>146.048g *</span></span> 0.85g</span>
so we would need 0.00582000438 moles of NH3 to have the same number of molecules.
One mole of NH3 is 17.030519999989988 grams (i added each atoms mass). so 0.00582000438 moles of NH3 would be:
<span><span><span>= 17.030519999989988 g / </span><span>mole * </span></span>0.00582000438moles</span>
that equals 0.09911770099 grams.
so 0.09911770099 grams is the answer if you round that you get about 0.1 grams
