Topic 1- Atomic Structure and the Periodic Table

Question 1

What do the electrons orbit the nucleus in?

Answer 1

Orbitals.

Question 2

Which part of the Atom takes up the most volume?

Answer 2

The orbitals.

Question 3

What is the relative mass of an electron?

Answer 3

0.0005

Question 4

Define an isotope?

Answer 4

Atoms of the same element with the same number of protons but different number of neutrons.

Question 5

What determines the chemical properties of an element?

Answer 5

The number and arrangement of electrons.

Question 6

Isotopes of an element have slightly different…… …….. to each other

Answer 6

Isotopes of an element have slightly different physical properties to each other, like density or rates of diffusion, as physical properties depend more on the mass of an atom.

Question 7

Define the Relative atomic mass.

Answer 7

The weighted mean mass of an atom of an element compared to 1/12th of the mass of an atom of Carbon-12.

Question 8

Define Relative isotopic mass.

Answer 8

The mass of an atom of an isotope compared with 1/12th of the mass of an atom of Carbon-12.
(This is usually a whole number)

Question 9

How does removing electrons from shells affect the ionisation energy?

Answer 9

The shell shrinks slightly as there is less repulsion between electrons within the shell (so distance is less) and ionisation energy increases.

Question 10

What trend on the periodic table do ionisation energies have?

Answer 10

Ionisation energies decrease down the periodic table.

Question 11

Define the first ionisation energy

Answer 11

The energy required to remove 1 electron from each atom in 1 mole of gaseous atoms to form one mole of gaseous 1+ ions.

Question 12

Define the second ionisation energy

Answer 12

The energy required to remove 1 electron from each 1+ ion in 1 mole of gaseous ions to form 1 mole of gaseous 2+ ions.

Question 13

Write an example equation of the second ionisation energy using the letter E.

Answer 13

E+ —> E 2+ + e-

Question 14

What provides evidence for existence of different sized shells?

Answer 14

Ionisation energy.

Question 15

Name 3 things that will affect the ionisation energy

Answer 15

Shielding ( the number of electrons between the outermost electron and the positive nucleus, which reduce the attraction)

Number of protons ( more protons the greater the attraction )

The size of the atom ( the distance between the outer electron and the positive nucleus).

Question 16

What is meant by ‘periodicity’?

Answer 16

A repeating pattern in a property across a period of the periodic table.

Question 17

A high ionisation energy means that there is a ……. attraction between……….. ………… therefore ……. ……. is needed to overcome the attraction and remove the electron

Answer 17

A high ionisation energy means there’s a strong attraction between the electron and the nucleus so more energy is needed to overcome the attraction and remove the electron.

Question 18

Give an equation for the first ionisation energy of oxygen

Answer 18

O (g) —-> O+ (g) + e-

Question 19

Atomic radius ….. across a period. Why?

Answer 19

Decreases.
The number of protons (therefore positive charge) increases meaning electrons are pulled closer to the nucleus making the atomic radius smaller.
(shielding doesn’t happen across a period only in extra shells)

Question 20

Generally it requires …. …. to remove an electrons from a higher energy subshell than a lower energy subshell.

Answer 20

More energy

Question 21

In general, elements with singly filled or full subshells are more ……. than those with partially filled subshells so have ……. ionisation energies

Answer 21

In general, elements with singly filled or full subshells are more STABLE than those with partially filled subshells so have HIGHER ionisation energies

Question 22

Repulsion between two electrons in an orbital means that electrons are …………. to remove from …….. …….

Answer 22

Repulsion between two electrons in an orbital means that electrons are easier to remove from shared orbitals.

Question 23

How many electrons can an S subshell hold?

Answer 23

2

Question 24

How many electrons can a p subshell hold?

Answer 24

6

Question 25

How many orbitals can a d subshell

Answer 25

10

Question 26

Which two elements are exceptions in electron configurations?

Answer 26

Cr: 1s”2, 2s”2, 2p”6, 3s”2,3p”6, 4s”1, 3d”5
Cu: 1s”2, 2s”2, 2p”6, 3s”2,3p”6, 4s”1, 3d”10

Question 27

Why are the 2 elements exempt from the usual configuration?

Answer 27

As It creates a more stable overall structure

Question 28

Orbitals of exactly the same energy are called……

Answer 28

degenerate.

Question 29

What is an electron in when it’s said to be in its lowest possible energy level?

Answer 29

It’s ground state.

Question 30

How does an electron move to a higher energy level?

Answer 30

Takes in energy from the surroundings

Question 31

What is another word for moving to a higher energy level?

Answer 31

The electron is excited

Question 32

What do electrons do as they drop down an energy level?

What do they definitely not do?

Answer 32

Release energy.

As they drop down the energy level it just jumps its NOT CONTINUOUS.

Question 33

Why are there lines on an emission spectrum?

Answer 33

Because energy levels have fixed values of light frequencies

Question 34

What does atomic emission spectra support the idea of?

Answer 34

Quantum shells

Question 35

What is an orbital?

Answer 35

An orbital is a region within an atom that can hold two electrons with opposite spins.

Question 36

The electrons in an orbital can be shown as arrows. What property is represented by these arrows?

Answer 36

Spin

Question 37

when should the term “relative formula mass” be used?

Answer 37

When compounds have giant structures