HELP- Mara adds 4 tablespoons of water to the sand, 7 tablespoons to the gravel, and 5 tablespoons to the
Calculate the porosity of each of Mara's samples using this formula, and record the results in the char
% porosity = (amount of water added to sample = total sample volume) x 100
"Total sample volume" is the amount of soil, sand, or gravel. A half cup is equal to 8 tablespoons.

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )

catya your not at all which answer i've seen you do this on another question!