Answer:
[Ne] 3s² 3d³
Explanation:
According to aufbau's principle of filling electronic orbitals, the sublevels with lower energies are filled up before those with higher energies.
One important to know about this principle is that sublevels do not fill in numerical order.
The order of filling is;
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f e.tc
From the given choices the wrong one is;
[Ne] 3s² 3d³
3p fills up before 3d;
Answer:
Mass = 8 g
Explanation:
Given data:
Mass of MgO formed = 20 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂ from balance chemical equation:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen required:
Mass = number of moles × molar mass
Molar mass of O₂ is 32 g/mol
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
Answer:
679.32 kJ
Explanation:
Heat required = number of moles * latent heat of fusion of water
So since we are given the mass of water and not the number of moles our first step is to calculate the number of moles of water available,
heat required = 111.0 mol * 6.12 kJ/mol
= 679.32 kJ
Answer: Neon
Explanation:
First, we'll use the ideal gas law, pV = nRT, to solve for the moles of unknown gas (n)
So putting all the values we get:
2.00 x 5.60 = n x 0.0821 x 273
n x 0.0821 x 273 = 2 x 5.60
22.4133n = 11.2
n = 0.499 moles
So the molar mass of the gas will be 10.1/0.499
= <u>20.24 g/mol</u>
The molar mass corresponds to Neon gas. Therefore, the identity of the gas is Neon