B should be 20 because only 1 oxygen goes into water
C is hydrogen because 2 hydrogens go into each water
Can't read anything beyond c
Lewis structure :
•• •• ••
:Cl• •N • •Cl:
•• • ••
•
:Cl:
••
The dots around the respective atoms represent the number of valence electrons each of the corresponding atoms have. Since nitrogen is more electronegative it is placed within the middle, it can also form the 3 covalent bonds, unlike chlorine which can only form 1 and thus is in the middle of the diagram. This structure has gained stability in that all of the atoms have 8 electrons in its outermost shell, if you were to count the shared electrons for each atom.
Answer:
The correct option is the second option
Explanation:
Generally, the aim of science is to understand a particular concept in the best and the most correct way possible; hence experiments are done and repeated to ensure an explanation is actually true about a concept or need modification.
The atomic models have also been a "beneficiary" of this process. The different atomic models are usually been improved upon as scientists leaned more. For example, the Dalton's atomic theory has been modified to a more correct atomic description; some of which are shown below
(1) Dalton's theory suggested that an atom is the smallest unit of a molecule. We know now from different experiments (by J. J Thompson and Rutherford) that atoms are not the smallest molecules and are made up of smaller particles known as protons, neutrons and electrons.
(2) Dalton's theory suggested that atoms of the same elements are alike in all aspects. The knowledge of isotopy shows this is not always the case. As atoms of the same elements (isotopes) have the same atomic number but different mass number; hence cannot be said to be the same in all aspects.
(3) Dalton's theory also suggested that when atoms react, they do so in fixed, simple whole number ratio. The knowledge of organic chemistry shows atoms do not always react in simple whole number ratios
There are several modifications to different postulations by scientists that have also occurred aside from this, hence the most correct answer is that "As scientists learned more, they modified the atomic model"
Explanation: Pollution in urban streams (commonly caused by improperly disposed waste and/or acid rain) always has a negative effect on the environment. <em>Urban rivers are extremely polluted in some areas</em>, such as India. Actions have been taken to clear the streams, and progress has been made.
Hope this helps!
