WEEK3

Question 1

What is electron configuration?

Answer 1

The electron configuration of an element describes how electrons are distributed in its atomic orbitals. They follow a sequence in which all electron containing atomic sub-shells are placed in a sequence.

Question 2

what is electron configuration for sodium

Answer 2

1S2,2S2,2P6,3S1

Question 3

An alternative way of writing electron configuration is by using the symbol of..?

Answer 3

Noble gasses

Question 4

Write the electronic configuration for sodium, aluminium and calcium using the symbol of noble gasses

Answer 4

Al: [Ne]3s2,2p1

Question 5

write the electron configuration for the first 10 elements (include noble gas notation)

Answer 5

refer to lecture o1c

Question 6

what is the maximum number of electrons that can by held by each shell, n=1, n=2, n=3, n=4

Answer 6

2, 8, 18, 32

Question 7

what is the maximum number of electrons that can be held by each subshell, l=0, l=1, l=2, l=3. s,p,d,f

Answer 7

2, 6, 10, 14 respectively

Question 8

what is the Aufbau principle?

Answer 8

Electrons will occupy orbitals having lower energy first before higher energy orbitals

Question 9

State the Pauli Exclusion Principle

Answer 9

• a maximum number of two electrons each having opposite spins, can fill an orbital
  -if the principle, azimuthal and magnetic numbers are the same for two electrons, they must have opposite spin.

Question 10

Hund’s Rule

Answer 10

States that every orbital in a given sub-shell is singly occupied by electrons before a second electron is filled in an orbital

Question 11

How is the Periodic Table ordered?

Answer 11

Elements are ordered according to their increasing atomic number

Question 12

Who arranged the periodic table?

Answer 12

Dmitri Mendeleev

Question 13

What do horizontal rows represent?

Answer 13

Periods
-Each period is assigned a number 1 - 7 indicating the principle quantum number

Question 14

what do vertical columns represent?

Answer 14

groups (families) each group is assigned a number from 1 to 18 indicating the number electrons in their outer most shell

Question 15

What does each row(period) represent?

Answer 15

A new Electron shell. Therefore; elements in the same period have the same number of shells

Question 16

What do elements in the same vertical column (group) have in common?

Answer 16

They have the same number of valence electrons and have similar propertis

Question 17

Each period is assigned a number (1to7. what quantum number does this indicate

Answer 17

principle quantum number (n)

Question 18

each group is assigned a number (1through18). what does this indicate?

Answer 18

The number of valence electrons in the outermost energy level of its element

Question 19

What are group 1 elements? describe their properties.

Answer 19

Alkali metals: Highly reactive metals, soft, low melting points

Question 20

What are group 2 elements? describe their properties

Answer 20

Alkaline Earth Metals: Reactive metals, less reactive than alkali metals

Question 21

What are group 17 elements?

Answer 21

Halogens: Highly reactive nonmetals, form salt with metals

Question 22

What is group 18?

Answer 22

Noble gasses-inert, non-reactive gasses with full valence shells

Question 23

Transition Metals

Answer 23

• starting from fourth period, 10 transition elements per period occupy the central part of the table
• because of the presence of d-orbitals the vertical columns of these elements are called B-groups

Question 24

Lanthanides and Actinides

Answer 24

-have electrons in the f orbital
-14 elements per series