Although you have not provided the circled electron, I can help you with a wide explanation.
1) Atomic number of manganese is 25. That means that it has 25 protons and 25 electrons.
2) Those 25 electrons are distributed (electron configuration) as per the quantum rules:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵
3) The most reasonable is that you have been asked to give the possible quantum numbers for an electron in the 4s or 3d.
4) Those are 7 electrons and these are their possible sets of quantum numbers:
i) For the two electrons in 4s:
n is the main energy level so n = 4
l tells the kind of orbital, which is s, so l = 0
ml is also 0 (it can be from -l to + l, so given that l i s0, ml is 0)
ms: one is +/12 and the other is -1/2 (this is the spin number).
ii) For the 5 electrons in 3d
n = 3
l can be 0, 1, or 2
if l = 0, then ml = 0
if l = 1, then ml can be -1, 0 , or 1 (from - l to + l)
ms can be either +1/2 or - 1/2 (spin)
Answer:
A. tungsten
Explanation:
Tungsten is a material which high melting point ie. does not melt easily incase of high temperature
Significant figures are numbers that are not 0s, but they are included if they are between two numbers:
There are three significant figures, 304
Hope this helps! :)
Answer:
n = 1.075 moles
Explanation:
Given that,
Mass of oxygen = 34.4 gram
The molar mass of oxygen gas = 32 g/mol
We need to find the number of moles of oxygen. We know that,
No. of moles = given mass/molar mass
So,
So, there are 1.075 moles in 34.4 g of Oxygen gas.
