Answer : The correct option is, Only Student B
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 nitrogen has '5' valence electrons and hydrogen has '1' valence electron.
Therefore, the total number of valence electrons in
= 5 + 3(1) = 8
According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.
The Lewis dot structure of student A is wrong because there is a coordinate bond present between the nitrogen and hydrogen is not covalent.
Thus, the correct Lewis-dot structure of
is shown by the student B.
Mass of lead (II) chromate is 51 g. The molecular formula is
and its molar mass is 323.2 g/mol
Number of moles can be calculated using the following formula:

Here, m is mass and M is molar mass.
Putting the values,

Therefore, number of moles of lead (II) chromate will be 0.1578 mol.
Answer:
A = 674.33mmHg
B = 0.385atm
Explanation:
Both question A and B requires the application of pressure law which states that the pressure of a fixed mass of gas is directly proportional to its temperature provided that volume is kept constant.
Mathematically,
P = kT, k = P / T
P1 / T1 = P2 / T2 = P3 / T3 =.......= Pn/Tn
A)
Data:
P1 = 799mmHg
T1 = 50°C = (50 + 273.15) = 323.15K
P2 = ?
T2 = 273.15K
P1 / T1 = P2 / T2
Solve for P2
P2 = (P1 × T2) / T1
P2 = (799 × 273.15) / 323.15
P2 = 674.37mmHg
The final pressure is 674.37mmHg
B)
P1 = 0.470atm
T1 = 60°C = (60 + 273.15)K = 333.15K
P2 = ?
T2 = 273.15K
P1 / T1 = P2 / T2
Solve for P2,
P2 = (P1 × T2) / T1
P2 = (0.470 × 273.15) / 333.15
P2 = 0.385atm
The final pressure is 0.385atm
Answer:

Explanation:
Hello there!
In this case, given the neutralization of the acetic acid as a weak one with sodium hydroxide as a strong base, we can see how the moles of the both of them are the same at the equivalence point; thus, it is possible to write:

Thus, we solve for the molarity of the acid to obtain:

Regards!
Answer:
Neon
Explanation:
1s² 2s² 2p⁶ 3s¹ or [Ne] 3s¹
The outer most shell is the 3s¹.
For this atom to achieve stability, if it loses the electron in the 3s shell, it would resemble an inert element with a complete octet configuration. Therefore, the atom would be like:
1s² 2s² 2p⁶ which is the configuration of Ne