Table of Contents
Why is work function half of ionisation energy?
The removal of the electrons from a sea of electrons needs less energy (generally) since they are attracted to many kernels at the same time, due to which the forces cancel out, resulting in free electrons. Hence, the work function is generally lower than the ionization energy for a particular element.
How does the value of work function influence the kinetic energy?
Threshold energy is equal to the work function of the element. Hence work function= Energy of photon – Kinetic energy of the metal. So as the work function of metal increases the kinetic energy of the emitted photo electron decreases.
What is the relationship between the activity of a metal and its ionisation energy?
The higher the first ionization energy, the higher the reactivity of the metal. The lower the first ionization energy, the higher the reactivity of the metal. The reactivity of a metal is not related to its first ionization energy.
Why do metals have lower ionization energy?
Metals typically have only a few valence electrons. Because of this, those electrons are only loosely bound to the nucleus and are therefore free to participate in metallic (or ionic) bonding.
Why is work function energy different from ionisation energy?
Ionisation Energy is the energy required to remove the outermost electron in an atom in its ground state to infinity, ie. Work Function, on the other hand, is the energy required to remove an electron from the surface of a metal to the vacuum level outside. Obviously, Ionisation Energy is greater than Work Function.
Is work function equal to ionisation energy?
The work function corresponds to the minimum amount of energy needed to remove an electron from the metal. In metals, work function and ionization energy are the same. The work function of a surface is strongly affected by the condition of the surface.
What is meant by work function of a metal How does the value of work function?
Work Function : The minimum energy required to free an electron from metallic surface is called the work function. Smaller the work function, larger the kinetic energy of emitted electron.
What is meant by work function of a metal How does the value?
The work function of a given metal can be defined as the amount of energy which is required to pull out an electron from an atom. The kinetic energy of emitted photoelectrons is equal to the difference between incident energy and the work function of the metal. ∴12mv2=hν−W. 1.
Why do metals with low ionization energy very reactive?
The reactivity of the metal inversely correlates to its first ionization energy. That means that if a metal has a very low ionization energy then it is very reactive. Metals react by giving out electrons so if they can lose their electrons easily then they can react very fast.
The distinction between metal and non-metal elements is most closely related to … the number of electrons in the outer-shell.
Why do metals have the lowest en values?
Electronegativity is a measure of the ability of an atom to attract the electrons when the atom is part of a compound. Since metals have few valence electrons, they tend to increase their stability by losing electrons to become cations. Consequently, the electronegativities of metals are generally low.
Why does the ionization enthalpy gradually decreases in a group?
Answer: Ionization enthalpy gradually decrease in a group because the nuclear charge on valence electrons decreases on moving down a group, hence, the electrons are held loosely and also the atomic size increases down a group.