_NaHCO(s) --> _CO2+_NaCO(s)+_H2O

balance the equation

The balanced equation :

2NaHCO₃⇒CO₂ + Na₂CO₃+H₂O

Given

Reaction

NaHCO(s) --> _CO2+_NaCO(s)+_H2O

Required

The balanced equation

Solution

Maybe the equation should be like this :

NaHCO₃⇒CO₂ + Na₂CO₃+H₂O

Give a coefficient

NaHCO₃⇒aCO₂ + bNa₂CO₃+cH₂O

Make an equation

Na, left=1, right=2b⇒2b=1⇒b=1/2

H, left=1, right=2c⇒2c=1⇒c=1/2

C, left=1, right=a+b⇒a+b=1⇒a+1/2=1⇒a=1/2

The equation becomes :

NaHCO₃⇒1/2CO₂ +1/2Na₂CO₃+1/2H₂O x2

2NaHCO₃⇒CO₂ + Na₂CO₃+H₂O

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72