5 What substance would do the best job of cleaning pots and
pans?
A
A substance with a pH of 7
B
A substance with a pH of 2
C
A substance with a pH of 4
D
A substance with a pH of 8

D . A substance with a pH of 8

Explanation:

pH stands for "Potential for Hydrogen." This is an indicator of a solution's acidity or alkalinity. It is also used to tell which chemicals are great for cleaning.

pH 7 and pH 8 are both considered "neutral pH," thus, solutions with these pH are often used as dishwashing detergents because they do not destroy the surfaces of objects. However, pH 8 is said to be more alkaline in nature. This allows it to destroy the residues, such as fats and oils, in pots and pans. It is the pH of baking soda.

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:

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).