Explanation:
The number of moles of solute present in liter of solution is defined as molarity.
Mathematically, Molarity = 
Also, when number of moles are equal in a solution then the formula will be as follows.

It is given that
is 8.00 M,
is 7.00 mL, and
is 0.80 M.
Hence, calculate the value of
using above formula as follows.



= 70 ml
Thus, we can conclude that the volume after dilution is 70 ml.
Answer:
Option-1 (O²⁻) is the correct answer.
Explanation:
All given anions contains same charge. So, we can ignore the effect of charge on these anions.
As we know all given compounds belongs to same group (Group 6) in periodic table. And from top to bottom along the group the elements are placed as,
Oxygen O
Sulfur S
Selenium Se
Tellurium Te
Hence, moving from top to bottom along the group the number of shells increases. And with increase in number of shell the atomic or ionic radii increases. As Oxygen is present at the top of the group, therefore, it has the smallest radius due to less number of shells.
Most solids a) are dense and difficult to compress.
Most solids are closely compacted, their molecules are close together and vibrate. They don't move freely like gas or water molecules do.
They are difficult to be squeezed or flattened.