Percentage by mass is the mass of NaF present in 100 g of the solution.
the percentage by mass of NaF is 23.4 %
this means that in 100 g of solution, mass of NaF present is 23.4 g
the number of moles of NaF present - 1.33 mol
mass of NaF - 1.33 mol x 42 g/mol = 55.9 g
when there's 23.4 g of NaF - mass of solution is 100 g
therefore when there's 55.9 g of NaF - mass of solution is 100 / 23.4 x 55.9
= 239 g
mass of solution required is 239 g
Option B
dumbbell is the shape of 3p atomic orbital
<u>Explanation:</u>
Atomic orbitals are three-dimensional places inside an atom where there is a tremendous chance of detecting electrons. The p orbital, which develops in complexity and ought 2 spaces encompassing the atom core, or is defined as possessing a dumbbell pattern. The 3p atomic orbital is at energy level 3, as seen by the number 3 filed ere the character.
These orbitals have identical appearances but are arranged asymmetrically in location. p orbitals are wavefunctions with l=1. They ought an angular frequency that is ununiform at each angle. They have an appearance that is much defined as a "dumbbell".
The answer is SiO2
Since silicon has four valence electrons and each oxygen has 2, for every 1 silicon there must be 2 oxygen to fill in both element's outer shells satisfactorily. An alternative way to figure out the chemical formula is to simply swap the charges.
Silicon is a -4 and oxygen is a -2.
Oxygen's charge is brought down into subscript and set as the number of silicons in the chemical formula, making silicon Si2. Silicon's charge is brought down to make the number of oxygens in the chemical formula O4. The formula we have currently is Si2O4. Simplify it to get the empirical formula (divide by 2) and you get SiO2.
