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.
Answer:
6
Explanation:
number of protons equal number of electrons for the atom to be stable
I believe the answer is carbon dioxide
It is effected by diffusion (the power of smell and wind spread) but a solid is not.
Answer: 1.9 x 10²⁴ molecules Na
Explanation: To solve for the molecules of Na, we will use the Avogadro's number.
3.2 moles Na x 6.022 x10²³ molecules Na/ 1 mole Nà
= 1.9 x 10²⁴ molecules Na
