Answer:
Na and Cl
Explanation:
An ionic compound is solid at state room temperature. Therefore Na and Cl would be the correct answer :)
Answer:
12.8 g of
must be withdrawn from tank
Explanation:
Let's assume
gas inside tank behaves ideally.
According to ideal gas equation- 
where P is pressure of
, V is volume of
, n is number of moles of
, R is gas constant and T is temperature in kelvin scale.
We can also write, 
Here V, T and R are constants.
So,
ratio will also be constant before and after removal of
from tank
Hence, 
Here,
and 
So, 
So, moles of
must be withdrawn = (0.66 - 0.26) mol = 0.40 mol
Molar mass of
= 32 g/mol
So, mass of
must be withdrawn = 
The correct answer is Crystals.
Unlike sugar, salt is not made out of crystals, but both salt and sugar are made out of atoms, that is molecules, and can have ions.