Atomic Sturcture & Electron Structure

Question 1

What are the sub- atomic particles in an atom ?

Answer 1

Protons, neutrons, electrons

Question 2

What is the atomic number ?

Answer 2

Number of protons (electrons) in an atom

Question 3

What is the mass number?

Answer 3

Number of protons and neutrons together

Question 4

What is an isotope?

Answer 4

Same element (same protons) but different number of neutrons

Question 5

Relative atomic mass?(Ar)

Answer 5

Weighted mean mass of an atom of an element with 1/12 of the mass of an atom of carbon-12

Question 6

Relative isotopic mass?

Answer 6

Mass of an atom of an isotope compared with one twelfth of the mass of an atom of carbon -12

Question 7

What is an atomic orbital ?

Answer 7

Region within an atom around the nucleus that can hold up to 2 electrons with opposite spins

Question 8

Sub-shells?

Answer 8

S, p, d,f

Question 9

Orbitals in s p d f?

Answer 9

S -1
P -3
D-5
F-7

Question 10

Shape of s orbital ?

Answer 10

Spherical shape

Question 11

Shape of p -orbital ?

Answer 11

Dumb-bell shape

Question 12

Energy of the shells and sub -shells

Answer 12

The sub-shell closest to the nucleus has the lowest energy, within the shell the sub-shell energies increase in the order s,p,d,f.

Question 13

The aufbau principle?

Answer 13

Electrons fill orbitals of lowest energy first
1S1,2s1,2p6,3s2,4s2,3d10,4p6

Question 14

Transition elements

Answer 14

D-block element that forms an ion with an incomplete d sub -shell
Lose their 4s electron first when forming positive ions- cation

Question 15

Cr and Cu

Answer 15

Cr, 1s2 2s2 2s6 3s2 3p6 4s1 3d5
Cu, 1s2 2s2 2s6 3s2 3p6 4s1 3d10