We now that 6.022x10^23 atoms are in one mole, therefore:
Answer: 3.425x10^35 mol AgNO3
Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
Gaps and predictions Sometimes this method of arranging elements meant there were gaps in his horizontal rows or 'periods'. But instead of seeing this as a problem, Mendeleev thought it simply meant that the elements which belonged in the gaps had not yet been discovered. He was also able to work out the atomic mass of the missing elements, and so predict their properties. And when they were discovered, Mendeleev turned out to be right. For example, he predicted the properties of an undiscovered element that should fit below aluminum in his table. When this element, called gallium, was discovered in 1875 its properties were found to be close to Mendeleev's predictions. Two other predicted elements were later discovered, lending further credit to Mendeleev's table.
Answer : The correct option is, (a) the energy level.
Explanation :
As we know that there are four quantum numbers :
- Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4....
- Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1). For l = 0,1,2,3... the orbitals are s, p, d, f...
- Magnetic Quantum Number : It describes the orientation of the orbitals. It is represented as . The value of this quantum number ranges from . When l = 2, the value of will be -2, -1, 0, +1, +2.
- Spin Quantum number : It describes the direction of electron spin. This is represented as The value of this is for upward spin and for downward spin.
The first electron configuration quantum number describes the electron shell or the energy level of an atom. The value of 'n' ranges from 1 to the shell containing the outermost electron of that atom.
For example :
For :
(Because it is in 1st shell)
(Because it is in 's' orbital)
(Because l = 0)
(Because of the sign convention)
Hence, the correct option is, (a) the energy level.