Questions

Polarity :: 

The polarity of a molecule defines its other physical properties such as melting point, boiling point, surface tension, vapor pressure etc... Simply, polarity occurs when the electron distribution in a molecule is asymmetric. This results in a net dipole moment in the molecule. One end of the molecule is charged negative while the other gets a positive charge.

The polarization of a molecule greatly depends on the shape of the molecule. A diatomic molecule like HF mentioned above has no issue of shape. The net dipole moment is only due to the uneven distribution of electrons between the two atoms. However, when there are more than two atoms involved in making a bond, there are many complexities.

The water molecule is of bent shape. Therefore, when the two pair of electrons shared by oxygen with two hydrogen atoms is pulled towards oxygen, the net dipole moment results in the direction of the oxygen atom. There is no other force to cancel out the resultant dipole moment. Hence, the water molecule is highly polar.

Ammonia molecule is of a pyramid shape and the electronegative N atom pulls the electrons towards itself. The three N-H bonds are not in the same plane; hence the dipole moments created do not get canceled out. This makes ammonia a polar molecule.

However, the dipole moments sometimes get canceled due to the shape of the molecules, making the molecule non-polar. Carbon dioxide is such a molecule.

Delhi High Court has ordered a ban over online sale of medicines across India.

The Dubai Mall, located in downtown Dubai, UAE, consists of four levels with a floor area of 548,127  (5.9 million ) and has 1,200 retail outlets and over 160 food and beverage outlets. Construction began in 2004, with the mall opening its doors on 4 November 2008. 

The light reactions of photosynthesis supply the calvin cycle with ATP and NADPH.

Demand is said to be inelastic, when the demand for the good doesn't change much or it is negotiable when the price of the good changed.

Data Control Language (DCL):-statements to take care of the security and authorization.

Examples:

1. GRANT


2. REVOKE

Cost Estimating - Developing an approximation of the costs of the resources needed to complete  project activities.

Cost Budgeting - Aggregating the estimated costs of individual activities or work packages to establish a cost baseline

Cost Control - Influencing the factors that create cost variances and controlling changes to the project budget.