Answer:
Explanation:
He should use these for airborne sounds
MDF Fiberboard.
Gypsum Board.
Plasterboard.
Mineral Wool.
He should avoid using
The answer is: Dividing the number of molecules in the sample by Avogadro's number.
The Avogadro’s number is the number of atoms in 12 grams of the isotope carbon-12 (¹²C).
Na is Avogadro number or Avogadro constant (the number of particles, in this example carbon, that are contained in the amount of substance given by one mole).
The Avogadro number has value 6.022·10²³ 1/mol in the International System of Units; Na = 6.022·10²³ 1/mol.
For example:
N(Ba) = 2.62·10²³; number of atoms of barium.
n(Ba) = N(Ba) ÷ Na.
n(Ba) = 1.3·10²⁴ ÷ 6.022·10²³ 1/mol.
n(Ba) = 2.158 mol; amount of substance of barium.
Explanation:
firstly firstly we are to calculate the number of moles of ammonia and using the mole concept of two moles of ammonia gives one mole of ammonium sulphate we can calculate the number of moles of ammonium sulphate and mass
from n=m/mr
Answer:
C. Tetrahedral
Explanation:
Tetrahedral would be the correct choice because the central atom has 4 domains (1 bond counts as 1 domain so 4 bonds =4) and no lone pairs which means it has tetra (which translates to four) domains hence tetrahedral.