Classification of Elements & Periodicity in properties

Who proposed periodic law for the first time

• Henry Mosely

• Mendeleev

• Pauling

• Newlands

Which element has highest electron gain enthalpy

• Chlorine

• Fluorine

• Sodium

• Magnesium

Identify the isoelectronic species from the following

• Na⁺, Na

• Mg²⁺, O^-

• Ne, Mg2+

• N^-, Na

Modern periodic law is based on________

• No. of protons

• No. of electrons

• No. of neutrons

• None of these

The name of the element with atomic number 120

• ununnilium

• ununbium

• unnilbium

• unbinilium

According to modern periodic law the physical & chemical properties of elements are periodic function of their _______

• atomic number

• atomic weight

• atomic volume

• atomic size

The size of cation is _____ the size of parent atom

• similar

• larger than

• same as

• smaller than

__________has highest electronegativity

• Chlorine

• Fluorine

• Sodium

• Magnesium

Isoelectronic species have ______

• same number of protons

• same number of neutrons

• same number of electrons

• none of these

The enthalpy change accompanied by the addition of an electron to neutral gaseous atom to form a negative ion is called _______

• Ionisation enthalpy

• Electron gain enthalpy

• Electronegativity

• Lattice enthalpy