A normal zinc (Zn) atom has 30 protons in its nuclear so that there are 30 electrons to make the atom be balanced of charge. The electrons are arranged by a rule that 1s2,2s2,2p6,3s2,3p6,4s2,3d10 (see more: electron configuration). A Zinc (Zn) atom contains 30 protons inside the nucleus, and 31 electrons outside the nucleus. Calculate the number of moles of electrons required. Convert the moles of electrons into coulombs of charge. Calculate the current required. Example: What current is required to produce 400.0 L of hydrogen gas, measured at STP, from the electrolysis of water in 1 hour (3600 s)? Calculate the number of moles of H 2. (Remember, at STP, 1 mole of. Number of Electrons (with no charge): 30. Zinc - Zn (EnvironmentalChemistry.com)- Comprehensive information for the element Zinc - Zn is provided by this page. The electrons that aren't the valence electrons are called core electrons. These core electrons do not participate in the chemical bonding and core electrons are.

Electrochemical Cell Potentials

The cell potential (voltage) for an electrochemical cell can be predicted from half-reactions and its operating conditions (chemical nature of materials, temperature, gas partial pressures, and concentrations).

A cell's standard state potential is the potential of the cell under standard state conditions, which is approximated with concentrations of 1 mole per liter (1 M) and pressures of 1 atmosphere at 25^oC.

To calculate the standard cell potential for a reaction

• Write the oxidation and reduction half-reactions for the cell.
• Look up the reduction potential, E^o_reduction, for the reduction half-reaction in a table of reduction potentials
• Look up the reduction potential for the reverse of the oxidation half-reaction and reverse the sign to obtain the oxidation potential. For the oxidation half-reaction, E^o_oxidation = - E^o_reduction.
• Add the potentials of the half-cells to get the overall standard cell potential.

Example: Find the standard cell potential for an electrochemical cell with the following cell reaction.

Number Of Electrons In Zinc

• Write the half-reactions for each process.
Zn(s) ' NOSAVE height=14 width=15> Zn²⁺(aq) + 2 e^-

Cu²⁺(aq) + 2 e^{-' NOSAVE height=14 width=15>} Cu(s)

• Look up the standard potentials for the redcution half-reaction.
E^o_{reduction of Cu2+} = + 0.339 V
• Look up the standard reduction potential for the reverse of the oxidation reaction and change the sign.
E^o_{reduction of Zn2+} = - 0.762 V

E^o_{oxidation of Zn} = - ( - 0.762 V) = + 0.762 V

• Add the cell potentials together to get the overall standard cell potential.

Zinc Element Number Of Protons

Determining Non-Standard State Cell Potentials

To determine the cell potential when the conditions are other than standard state (concentrations not 1 molar and/or pressures not 1 atmosphere):

• Determine the standard state cell potential.
• Determine the new cell potential resulting from the changed conditions.
• Determine Q, the reaction quotient.
• Deternine n, the number of electrons transferred in the reaction 'n'.
• Determine E_cell, the cell potential at the non-standard state conditions using the Nernst equation.

E_cell = cell potential at non-standard state conditions
E^o_cell = standard state cell potential
R = constant (8.31 J/mole K)
T = absolute temperature (Kelvin scale)
F = Faraday's constant (96,485 C/mole e^-)
n = number of moles of electrons transferred in the balanced equation for the reaction occurring
in the cell
Q = reaction quotient for the reaction. aA + bB ' NOSAVE height=14 width=15> cC + dD,

If the temperature of the cell remains at 25^oC, the equation simplifies to:

E_cell = E^o_cell - (0.0257/n) ln Q

or in terms of log₁₀

E_cell = E^o_cell - (0.0592/n) log Q

Example: Predict the cell potential for the following reaction when the pressure of the oxygen gas is 2.50 atm, the hydrogen ion concentration is 0.10 M, and the bromide ion concentration is 0.25 M.

• Calculate the standard cell potential for the reaction, E^o_cell, using the tabled values:

oxidation:	4 Br-(aq) ' NOSAVE height=14 width=15> 2 Br2(l) + 4 e-	Eoox. = - Eored. = - (+ 1.077 V) = - 1.077 V
reduction:	O2(g) + 4 H+(aq) + 4 e- ' NOSAVE height=14 width=15> 2 H2O(l)	Eored. = + 1.229 V
overall:	O2(g) + 4 H+(aq) + 4 Br-(aq) ' NOSAVE height=14 width=15> 2 H2O(l) + 2 Br2(l)	Eocell = + 0.152 V

• Determine the new cell potential resulting from the changed conditions.
• Calculate the value for the reaction quotient, Q. (Note: We calculate Q using molar concentrations for solutions and pressures for gases. Water and bromine are both liquids, therefore they are not included in the calculation of Q.)
• Calculate the number of moles of electrons transferred in the balanced equation, n.
n = 4 moles of electrons
• Substitute values into the Nernst equation and solve for the non-standard cell potential, E_cell.

Number Of Outer Electrons In Zinc

How many valence electrons does zinc have?

1 Answer

Explanation:

Zinc is located in period 4, group 12 of the periodic table and has an atomic number equal to 30.

Zinc 67 Protons Neutrons Electrons

This means that neutral zinc atom has a total of 30 electrons surrounding its nucleus. To see how many of these electrons are valence electrons, write the electron configuration of a neutral zinc atom.

#'Zn': 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10#

or, if you use the noble gas shorthand notation

#'Zn': ['Ar'] 4s^2 3d^10#

Notice that the outermost shell, which for zinc is the fourth shell, #'n=4'#, has two electrons.

Number Of Electrons In Outer Shell Zinc

This means that zinc can lose the two electrons located in the 4s-orbital to be become the #Zn^(2+)# cation.

#'Zn'^(2+): ['Ar'] 3d^10#

Notice that the 3d-orbital is completely filled, which means that these electrons behave like core electrons and cannot be considered valence electrons.

Therefore, zinc has only 2valence electrons, both located in the 4s-orbital.

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