The element with lowest ionization energy among the following is:
When we go down in a group shell increase and size increase and due to large size of atom electron can easily be removed. Thats option is C.
Isoelectronic species have:
Isoelectronic are the species having same number of electrons.
A positive charge means the shortage of an electron.
The cause of periodicity of properties of elements is due to the repetition of similar:
The cause of periodicity of properties of elements is due to the repetition of similar electronic configuration of their atoms in the outermost energy shell after certain regular interval.
Tendency of an atom in a molecule to attract the shared pair of electron towards itself is called:
The tendency of an atom in a molecule to attract the shared pair of electrons towards itself is called its electronegativity.
Electronegativity is a dimensionless property since it is only a tendency. It only indicates the net result of the tendencies of different elements to attract the bond forming electron pair.
Identify the smallest ion among the following:
Al3+ because they all have the same number of electrons, however Al3+ has the most protons and therefore greatest nuclear charge. In Al3+, the same number of electrons are being attracted by more protons in the nucleus, so the electrons are being pulled closer to the nucleus, reducing the size of the ionic radius.
Na+ is smaller than Na atom because:
According to the electronic configuration of sodium(Na),it has 1 valence electron(2,8,1).So it loses one electron to form a cation and becomes sodium cation (Na+).As it loses one electron ,the outermost shell has 0 electrons (i.e it gets eliminated ) and Na+ has only 2 shells. Hence, it lost one of its shell, the sodium ion is smaller than the sodium atom.
Electron gain enthalpy is most negative for:
The negative electron gain enthalpy of fluorine is less than that of chlorine. It is due to small size of fluorine atom. As a result, there are strong interelectronic repulsions in the relatively small 2p orbitals of fluorine and thus, the incoming electron does not experience much attraction.
Among the following the element with highest first ionization energy is:
Carbon has the highest first ionisation energy because ionisation energy decreases down the group and increases from left to right in a period.
Which of the following elements will have the largest atomic radius?
Strontium has the highest atomic radii because it on the group atomic radius increases also it belongs to 4D so if there is doubt of Lanthanide contraction then the size of 4D is largest followed by 3D and 5D has the smallest size.
For noble gases radius is measured as:
It is believed that Noble gases don't form (or rather don't easily form bonds). This way only Van der Waals radius is measured.
The rationale here is based on the fact that noble gases have very low chemical reactivity and their atomic radii are non bonded.
The electronegativity of following elements increases in the order of?
Electronegativity increases along a period and decreases down the group.Nitrogen is expected to have maximum electronegativity.
Which of following statement is incorrect regarding ionization enthalpy:
The option (d) represents incorrect statement. It states that
"Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value".
The correct statement is "Removal of electron from orbitals bearing lower n value is difficult than from orbital having higher n value".
The attraction between the nucleus and the electron present in orbital having lower n value is higher than the attraction between the nucleus and the electron present in orbital having higher n value.
Which of the following elements has the largest ionisation enthalpy?
Ionisation energy increases along a period. The very next elements C,N,O,F results F with higher ionisation energy.
Sum of atomic mass of all atoms present in one molecule of a molecular compound is
The mole concept, which we will introduce here, bridges that gap by relating the mass of a single atom or molecule in amu to the mass of a collection of a large number of such molecules in grams. As you learned, the mass number is the sum of the numbers of protons and neutrons present in the nucleus of an atom.
What happens to atomic radius on going from left to right in a period in a periodic table?
Atomic radius is generally decreases from left to right along a period because the electrons are added to same shell due to this they experience a great force from the nucleus. While atomic radiusincreases in group from top to bottom cause new shells are added and the electrons are bring away from the nucleus.
When an electron is added to neutral gaseous atom to convert it into a negative ion, the enthalpy change accompanying the process is called:
Electron affinity is defined as the change in energy (in kJ/mole) of a neutral atom (in the gaseous phase) when an electron is added to the atom to form a negative ion.
Which of the following is isoelectronic with F–?
F- is isoelectronic with Ne both have 10 electrons
Among the following elements element with highest ionisation enthalpy is:
Among the given molecules, N2 has highest ionization enthalpy.The reason behind is the stability of half-filled orbitals which makes it more stable than other elements in the given option list.
The largest atomic radius among the following is of:
Atomic radius decreases along period, the very next elements K ,Ca has K has higher atomic radius.
Electron gain enthalpy values of noble gases are positive because:
Electron gain enthalpy values of noble gases are positive because they have stable electronic configuration and thus have no tendency to take additionalelectron.