2 Atomic Structure

Question 1

Name and explain the different types of subatomic particles.

Answer 1

Protons
* located in the nucleus of the atom
* positive charge
* relative mass = 1

Neutrons
* located in the nucleus of the atom
* neutral charge
* relative mass = 1

Electrons
* located in the energy levels within the atom
* negative charge
* relative mass = 1/2000

Question 2

What happens if you change the amount of electron in an atom?

Answer 2

It creates an ion
* If the negative charge is increased (+ electrons), it leads to an anion
* If the negative charge is decreased (- electrons), it leads to a cation

Question 3

What happens if the amount of protons is changed?

Answer 3

It creates a new element

Question 4

What happens if the amount of neutrons is changed?

Answer 4

It creates isotopes

Question 5

What are the atomic and mass numbers?

Answer 5

The atomic number indicates the number of protons in the nucleus of the atom

The mass number is the number of protons and neutrons

• number of neutrons = mass - atomic number

Question 6

explain the “leyenda” of the periodic table

Answer 6

(^A)(vZ) X
- A= mass number (p+n)
- X = atomic symbol
- Z = atomic number (p)

Question 7

Explain the different charges that an atom can have.

Answer 7

Neutral atom: neutral charge, same amount of protons and neutrons
Positively charged atom: more protons than electrons, a cation
Negatively charged atom: more electrons than protons, an anion

Question 8

What are isotopes?

Answer 8

Isotopes are atoms of the same element that have different amounts of neutrons, they have the same atomic number (Z) put different mass numbers (A).
They have slightly different physical propertiew which is what enables their separation.

Question 9

Ehat is the relative atomic mass and how is it calculated?

Answer 9

The RAM is the average mass of an element considering all isotopes and their abundance.
RAM = ((%1/100) x A1) + ((%2/100) x A2)

Question 10

What is a mass spectrometer and how does it work?

Answer 10

The mass specrtometer is an instrument used to determine the relative atomic mass of an element. It can also show its isotopic composition.

It works by:
1. The sample is injeacted heated and vaporised , producing gaseous atoms
2. These gaseous atoms are bombarded by high energy electrons, generating positively charged atoms, ions (cations)
3. The positive ions are attracted to negatively charfed plates and accelerated in the electric field
4. The positive ions are deflected by magnetic field perpendicular to their path. The species with the smallest mass and highest charde will be deflected the most.
5. The ions hit the counter and electrical signals are generated. The height of each peak in the results indicates the relative abundance of the respective isotope.

Question 11

Explain the atomic orbitals.

Answer 11

There are main energy levels (n) which is where the electrons are located in orbitals. These energy levels are split into sub-levels (s, p, d, f), each containing two electrons.

Question 12

Explaining the Heisenberg’s uncertainty principle.

Answer 12

The velocity and position of an electron cannot be simultaneously measured with high precision. Therefore, atomic orbitals are used to describe the probability of finding an electron in an area of space.

Question 13

What are the shapes of the different orbitals?

Answer 13

S-orbitals have a spherical shape
P-orbitals have a dumbell shape and contain three versions which are alligned in different axis (x,y,z)

Question 14

What is the distribution and enery of the main energy levels

distribution: distance between levels

Answer 14

n=1 is the closest to the nucleus and it has the lowet energy (the higher the value of n, the more energy there is
As the energy levels reach infinity, they become closer and closer

Question 15

What are the three things one must take into consideration when drawing box diagrams?

Answer 15

1. the lowest energy orbitals are filled before the higher energy orbitals (Aufbau)
2. Each orbitals gets one electron first before adding the second electron (Hund)
3. Only two electros, of opposite spins, can occupy each orbital (Paulis)

Question 16

What are the two exceptions regarding electon configuration?

Answer 16

• Chromium (24Cr) - 4s1 3d5
• Copper (29Cu) - 4s1 3d10

Question 17

How does the light spectrum work?

Answer 17

As energy increases, frequency (amount of waves) also increases and wavelength decreases.

Question 18

Give in order the relevant names in the light spectrum.

Ordered from higher energy to lower energy

Answer 18

1. X-rays
2. Ultraviolet light
3. Visible light
4. Infrared
5. Microwaves

Question 19

What is the emission line spectrum?

Answer 19

It shows the transition to lower energy levels. The electrons have to reduce their energy to adapt to the energy in the lower levels as there is less
They emit colour so the little box thingy is black with lines of colour.

as n increases, energy also increases

Question 20

What is the absorption line spectrum?

Answer 20

It shows the transition to higher energy levels. Tthe electrons have to increase their energy to fit the one in the higher energy levels, therefore, they obtain it.
They absorb colour so the box thingy is coloured with black lines

As n increases, energy also increases

Question 20

What is the absorption line spectrum?

Answer 20

It shows the transition to higher energy levels. Tthe electrons have to increase their energy to fit the one in the higher energy levels, therefore, they obtain it.
They absorb colour so the box thingy is coloured with black lines

As n increases, energy also increases

Question 21

What happens when electron falls to a lower energy level?

Answer 21

It releases energy in the form of photons of light. The diffeerent energy levl the electron falls down to determines which type of light will be produced.
- N=1 - UV radiation
- N=2 - visible light
- N=3 - infrared light