Ionization enthalpy, IE, is also called ionization potential is the ability to remove the electron from the neutral gaseous atom. There is a trend observed in the periodic table for the IE value. As we go from left to right in a period, IE vale increases. While moving from top to bottom in a group, IE value decreases.
- The phenomenon of unexpected drop in IE1 values between Groups 2 and 13, in period 2 and period 4 is due to the introduction of d-orbitals in the case of period 4 elements.
- While moving in the period, there is the constant addition of electrons in the nucleus. The shell sie remains constant while electron pull increases from the nucleus, this leads to a reduction in the size of the atom. As the size decreases, it is difficult to remove the electron from the atom, and thus IE value increases in the case of period 2.
- When we study the case of period 4, there is an introduction of d-electrons. As the inner shell electron increases, there is an increase in the shielding effect. This shielding effect tends to decrease the nuclear attraction between the nucleus and outermost electrons. Ultimately this decreases the IE value in the fourth period. Such a phenomenon is absent in the case of group 2 elements.
- If we speak in terms of orbital energy, the IE value decreases while moving from top to bottom in the period. This is due to the fact that, as we go down in the periodic table, the number of shells increases, and the outermost electron is too far from the nuclear attraction, therefore it can be ejected out easily. This marks a decrease in IE value.
To learn more about ionization refer the link:
brainly.com/question/1558319
#SPJ4
When 0.5 moles of Zn react with 0.4 moles of HCL the limiting reactant will be HCL and excess reactant is Zn 0.3 moles excess and 0.2 moles Zn will be consumed in the reaction.
<h3>What is the limiting reactant in the given equation ?</h3>
STEP1- Write the balanced equation
Zn + 2HCL → ZnCl₂ + H₂
STEP2- calculate the moles according to the reaction
1mol of Zn requires → 2moles of HCL
0.5 moles of Zn requires→ 1mol of HCL
Given moles of HCL is 0.4
STEP3- Apply unitary method
0.5/x=1/0.4
0.5×0.4= x
0.2=x
STEP4- excess reagent left 0.5-0.2=0.3
Hence, the 0.3mole of excess Zn is left
Learn more about limiting reactions numericals.
brainly.com/question/12836695
#SPJ4
Answer: Positive, positive
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
is positive when randomness increases and is negative when randomness decreases.
Exothermic reactions are defined as the reactions in which energy is released in the form of heat and 
for the reaction comes out to be negative.
Endothermic reactions are defined as the reactions in which energy is absorbed in the form of heat and for the reaction comes out to be positive.
For a cold pack, the energy has to be absorbed for the dissolution of ammonium nitrate in water so that the surroundings feel cold.Thus as energy is absorbed, for the reaction comes out to be positive.
The solid form of ammonium nitrate is getting converted to ions and thus entropy increases and thus for the reaction comes out to be positive.
