I think the answer is a pure substance
<u>Answer:</u> The value of
for the net reaction is 
<u>Explanation:</u>
The given chemical equations follows:
<u>Equation 1:</u> 
<u>Equation 2:</u> 
The net equation follows:
As, the net reaction is the result of the addition of first equation and the second equation. So, the equilibrium constant for the net reaction will be the multiplication of first equilibrium constant and the second equilibrium constant.
The value of equilibrium constant for net reaction is:

We are given:


Putting values in above equation, we get:

Hence, the value of
for the net reaction is 
Yes, the atomic radius increases as you move down a group of elements.
this is true
going down leads to valence electrons that are further away from nucleus -> less electrostatic attraction -> less pull towards nuc. -> greater radius/volume taken
Answer:
Option D = No, when elements combine to form a new material, they have properties unique to the new materials.
Explanation:
When sodium contact with water it loses its one electron and thus gain positive charge. When there are more sodium atoms present and many atoms do this thus more positive ions are produced and these positive ions repeal each other at high speed and explosion occur.
But when it form compound with other material, it will not showed this behavior.
Example:
Consider the sodium chloride, when it dissolve in water sodium not showed explosion. In sodium chloride sodium already gives its electron to the chlorine and have stable electronic configuration. The sodium present in cationic form. When it dissolve, partial positive charge of water surrounds the Cl⁻ and partial negative charge of water surrounds the Na⁺ ion, ans sodium chloride gets dissolve into water without explosion.
Answer:
The correct option is;
A warm front is approaching the city and temperatures will increase
Explanation:
A low pressure forms by the movement of air away from a particular spot such that the pressure reduces. The movement of air away from a spot occurs when there is a boundary of warm and cold air such that the air moves to maintain a uniform temperature.
Low pressure centers are associated with warm fronts, resulting in the fall of barometric pressure or observed low pressure and are characterized by a rise in temperature.