A. Electrons fill orbitals with parallel spins until all the orbitals of the same energy are half filled then they go into sub-shells with anti-parallel (opposite) spin.
B. The electrons in the same atom cannot have the same four quantum numbers
C. There is maximum of two electrons is an orbital.
D. None
Related Mcqs:
- The octet rule does not always hold for which of the following elements _________________?
A. C
B. O
C. F
D. P - In the van der Waals equation (P + n2a / v2) (v – nb) = nRT which of the following statement is not true ?
A. n2a/v correct for the intermolecular forces.
B. nb correct for the volume occupied by gas molecules.
C. at high densities the equation reduces to the ideal gas law
D. all of the above statements are correct. - Which of the following statement is correct ?
A. size of Cl atoms > Cl- ion
B. size of Na+ ion < Na atom
C. size of Na atom < Na+ ion
D. Cl- < Na+ - Which statement is wrong ?
A. the amount of ozone layer is greater in the region close to the equator
B. ozone acts as filter for UV radiations
C. in the equatorial region it acts as pollutant
D. CFCs play effective role in removing O3 in the stratosphere - Which of the following is incorrect statement about nitrogen importance ?
A. It enhances plant growth
B. It is involved in the synthesis of protein and nucleic acids
C. it accelerates fruits and flowers growth
D. It is involved in the chlorophyll synthesis - Which statement is incorrect about catalyst___________________?
A. it is used in smaller amount
B. decrease activation energy
C. specific in action
D. it affects specific rate constant - Which one of the following statement is not correct about benzene ?
A. On hydrogenation 208 KJ/mole is liberated
B. C-H bond length in benzene is 1.09 A?
C. Molecular mass of benzene is 78.108
D. Resonance energy of benzene is 150.5 K Cal/mole - Identify the correct statement regarding CO_______________?
A. it combines with H2O to form carbonic acid
B. it reacts with red blood cells of haemoglobin
C. it is powerful oxidizing agent
D. it is used to prepare aerated drinks - Which of the following statements about isotopes is correct ?
A. Isotopes with odd atomic number are abundant
B. Isotopes with odd atomic number and even mass number are abundant
C. Isotopes with even atomic number and even mass number are abundant
D. Isotopes with even atomic number and odd mass no are abundant - The nucleus of an atom of every element will always contain____________________?
A. neutrons
B. protons and electrons
C. protons
D. protons and neutrons
