The nervous system and endocrine system play important roles in helping the body maintain homeostasis. The nervous system processes input when something is out of its optimal range. The nervous system can then determine the best course of action to correct the imbalance. Sometimes the nervous system stimulate the glands of the endocrine system to release hormones and other times, it can cause a response such as shivering or sweating to help return the body to its steady state. Calcium is a crucial nutrient used in many bodily processes from muscle contraction to blood clotting. The nervous and endocrine system work hand in hand to control calcium levels throughout the body.
Using the diagram, what action is taken when calcium levels are too high?

A) The thyroid glands release PTH.
B) The parathyroid glands release PTH.
C) The thyroid gland releases calcitonin.
D) The parathyroid glands release calcitonin.

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:

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.