Answer: A) polar molecule
Explanation: Polar molecules are molecules which contain atoms of different electronegativities.
Non polar molecules are molecules which contains atoms of same electronegativities.
Water is a polar covalent molecule formed by unequal sharing of electrons. Oxygen being more electronegative tend to keep the electron pair towards itself thus generating a partial negative charge. The hydrogen acquire a partial positive charge thus resulting in a polar molecule.
The bent shape is due to repulsion between lone pairs and bond pairs of electrons.
The branched structure isomer will require less energy to melt than the straight chain isomer
explanation
Branched structure isomer has weak intermolecular forces of attraction as compared to straight chain isomers. In addition the branched isomer has a low boiling point as compared to straight chain isomers. Since boiling require the of the intermolecular forces tend to have lower boiling point than straight chain
Answer: Option (b) is the correct answer.
Explanation:
When there are more number of hydroxide ions in a solution then there will be high concentration of 
or hydroxide ions. As a result, more will be the strength of base in that particular solution.
A base is strong when it readily dissociate into its ions in the solution. When a base is strong, then it does not matter at what concentration it is dissolved in the solution because despite of its low concentration it will remain a strong base.
Thus, we can conclude that out of the given options, the statement even at low concentrations, a strong base is strong best relates the strength and concentration of a base.
John Dalton was a scientist who proposed that all matter consists of atoms. At this stage, no one had yet discovered neutrons and the nucleus. As a result, Dalton's model consisted of a single atom i.e. the atom was the smallest object.
A mass spectrometer is an instrument that is able to see what is inside an atom. Scientists have been able to prove that the item is not the smallest object in the world. Atoms are made up of smaller objects called protons, neutrons and electrons.
We can, therefore, safely conclude that data from mass spectrometry has helped modern scientists to make modifications to Dalton's model. <span>
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Saturated hydrocarbons are organic compounds that contain only single bonds between the carbon atoms. They are known to be the simplest organic compounds. They are termed as such because they are saturated with water. Examples are the alkanes (ethane, methane, propane, butane, etc.).
