Why metallic character decreases across a period and increases down a group?
The atomic radius decreases as we move across a period because:
atomic mass increases.
atomic number increases.
more electrons are added.
effective nuclear charge increases.
Define atomic size. How does it vary in a period and in a group ?
Why do the elements in the same group have similar chemical properties?
Mischmetal is an alloy consisting mainly of
lanthanoid and actinoid metals
actinoid and transition metals
State the characteristics of groups in the periodic table.
Is aluminium a good conductor of electricity?
What is the radius of hydrogen atom?
Which orbitals have the highest shielding effect?
Most non-metallic among F, Cl, Br, I, and At is:
What is the element in Group 4 Period 4?
The size of iso electronic species F‑ , Ne and Na+ is affected by
Electron-electron interaction in the outer orbitals
None of the factors because their sizes the same.
Nuclear charge (Z)
Valence principal quantum number (n)
Which of the following is liquid at room temperature?
Hydrogen, potassium, sodium, lithium
- Hydrogen < lithium < sodium < potassium
- Potassium < hydrogen < lithium < sodium
- Hydrogen < potassium < sodium < lithium
- Potassium < sodium < lithium < hydrogen
The size if fluorine ion is greater than fluorine atom
An atom of phosphorus has the symbol
3115P. Give the number of protons, neutrons and electrons in an atom of phosphorus.
Number of protons __(A)___.
Number of neutrons __(B)___ .
Number of electrons __(C)___ .
- (A) - 15, (B) - 16, (C) - 15
- (A) - 15, (B) - 15, (C) - 15
- (A) - 15, (B) - 15, (C) - 16
- (A) - 16, (B) - 16, (C) - 15
The alkali metal with the smallest atomic radius is __________.
Define atomic size. Give its unit of measurement. In the modem periodic table what trend is observed in the atomic radius in a group and a period and why is it so?
What is the name of ion with the formula ?
- The number of electrons.
- The number of shells.
- Atomic mass
What is the smilarisimil and differences between Atom , Ion and molecules with their respective defination?
- Lithium > oxygen > carbon
- Oxygen > carbon > lithium
- Carbon > oxygen > lithium
- Lithium > carbon > oxygen
The atomic number of an element 'X' is 15 . Identify its position in the modern periodic table
Why are ionic compounds insoluble in kerosene and petrol?
Which of the following molecule does not have any lone pair of electrons on the central atom?
The atomic size of lithium is _____ than that of sodium.
Which factor is most responsible for the increase in boiling points of noble gases from to ?
Increase in polarisability
Decrease in polarisability
Decrease in Ionisation energy
- Nitrogen (N)
- Carbon (C)
- Phosphorus (P)
- Sulphur (S)