It changes the chemical composition of the magnesium into something else (whitish substance)
Answer: an element, feature, or factor that is liable to vary or change.
"there are too many variables involved to make any meaningful predictions"
Explanation:
The grams of N2 that are required to produce 100.0 l of NH3 at STP
At stp 1moles = 22.4 l. what about 100.0 L of NH3
= 100 / 22.4 lx1 moles = 4.46 moles of NH3
write the reacting equation
N2+3H2 =2NH3
by use of mole ratio between N2 to NH3 which is 1:2 the moles of N2 =4.46/2 =2.23 moles of N2
mass = moles x molar mass
= 2.23moles x 28 g/mol = 62.4 grams
The answers D) -60
Just subtract
Answer:
1) Ca: [Ar]4s²
2) Pm: [Xe]6s²4f⁵
Explanation:
1) Ca:
Its atomic number is 20. So it has 20 protons and 20 electrons.
Since it is in the row (period) 4 the noble gas before it is Ar, and the electron configuration is that of Argon whose atomic number is 18.
So, you have two more electrons (20 - 18 = 2) to distribute.
Those two electrons go the the orbital 4s.
Finally, the electron configuration is [Ar] 4s².
2) Pm
The atomic number of Pm is 61, so it has 61 protons and 61 electrons.
Pm is in the row (period) 6. So, the noble gas before Pm is Xe.
The atomic number of Xe is 54.
Therefore, you have to distribute 61 - 54 = 7 electrons on the orbitals 6s and 4f.
The resultant distribution for Pm is: [Xe]6s² 4f⁵.
