It is a scientific hypothesis. A scientific hypothesis must be testable, however there is a significantly more grounded necessity that a testable speculation must meet before it can truly be viewed as logical. This foundation comes essentially from crafted by the rationalist of science Karl Popper, and is called "falsifiability".
Answer: E
Explanation:
The lattice energy is the energy change when one mole of a crystal is formed from its components ions in its gaseous sate
Therefore lattice energy = heat of Sublimation+ ionization energy +electron affinity-(heat of formation)
Therefore lattice Energy = 109 +495 -328 +570.
Lattice energy = --923kjmol-1
Answer:
1 x 10^-4
Explanation:
Use the equation pH = -log[OH-}
Rearranging it [OH-] = 10^-pH
Plugging in we get [OH-] = 1 x 10^-4
Answer : The formal charge on the C is, (-1) charge.
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is, 
As we know that carbon has '4' valence electrons and hydrogen has '1' valence electron.
Therefore, the total number of valence electrons in
= 4 + 3(1) + 1 = 8
According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.
Now we have to determine the formal charge on carbon atom.
Formula for formal charge :


The formal charge on the C is, (-1) charge.
2 shells because if you do the electronic configuration:
2,7 which adds up to 9
7 stands for the group it in and it also stands for how many electrons are in the outer shell.
the amount of spaces stands for which period its in therefore it in period 2