Structure of Atoms

Question 1

What is an atom?

Answer 1

An atom is the smallest particle of an element which can take part in a chemical reaction and remain unchanged.

Atom means ‘cannot be divided’ into smaller particles.

Question 2

What are the main components of an atom?

Answer 2

• Proton
• Neutron
• Electron
• Nucleus

Question 3

Who proposed the atomic theory in 1808?

Answer 3

John Dalton

He states that all substances or matter is made up of dense spheres call

Question 4

What model did J.J. Thomson propose?

Answer 4

The Plum Pudding Model

Question 5

What did Rutherford’s 1911 atomic model propose?

Answer 5

That atoms are composed of a small, dense nucleus surrounded by electrons.

Question 6

What experiment did Rutherford conduct to support his atomic model?

Answer 6

The Gold Foil Experiment

Question 7

What was the conclusion of Rutherford’s Gold Foil Experiment?

Answer 7

Most alpha particles passed through the gold foil, indicating that atoms have a small, dense nucleus.

Question 8

What are the characteristics of an element?

Answer 8

An element is a substance made of just one type of atom and cannot be broken down into simpler substances by chemical means.

Question 9

How did Democritus contribute to atomic theory?

Answer 9

Democritus stated that all matter is made up of tiny particles called atoms.

Atom means ‘cannot be divided’

Question 10

What did Thomson’s atomic model compare the atom to?

Answer 10

A plum pudding, where the positively charged mass is the pudding and the negatively charged electrons are the plums.

Question 11

What is the charge of an atom overall?

Answer 11

An atom has a neutral charge because the number of protons equals the number of electrons.

A strong electrostatic force holds them together

Question 12

Fill in the blank: The electrons revolve around the nucleus in fixed circular paths called _______.

Answer 12

orbits

Question 13

What did Schrödinger contribute to atomic theory in 1926?

Answer 13

He proposed the Quantum Model, suggesting that electrons exist in a cloud around the nucleus.

Question 14

What is the size of the nucleus compared to the atom?

Answer 14

The nucleus is very small relative to the entire size of the atom.

Question 15

What is the significance of the year 1932 in atomic theory?

Answer 15

Chadwick discovered the neutron.

Question 16

True or False: Atoms can be divided into smaller particles.

Answer 16

False

Question 17

What was one of the key findings of the experiments conducted by Perrin around 1910?

Answer 17

That atoms really do exist.

Question 18

What is the definition of an element?

Answer 18

A substance that cannot be broken down into two or more simpler substances by chemical means.

Question 19

How many different elements have been discovered?

Answer 19

Over 100 different elements.

Question 20

Atoms consist of ___ charged particles.

Answer 20

positively

Question 21

The majority of the mass of the atom is in a small region called the ____

Answer 21

nucleus

Question 22

The nucleus is composed of ___ and ___

Answer 22

neutrons
protons

Question 23

What do all the numbers on an element ‘tile’ mean?

Answer 23

Smaller number: Atomic number (protons)
Centre: Symbol & name
Bigger number: Atomic mass

The symbol does not always look like the name!!! eg Lead is Pb

Question 24

What are the three sub-atomic particles?

Answer 24

Proton, Neutron, Electron

Each of these particles has distinct properties and roles in an atom.

Question 25

What is the relative mass and charge of a Proton?

Answer 25

Relative mass: +1, Relative charge: +1 ## Footnote Protons are positively charged particles found in the nucleus of an atom.

Question 26

What is the relative mass and charge of a Neutron?

Answer 26

Relative mass: 0, Relative charge: 0 ## Footnote Neutrons are neutral particles also located in the nucleus.

Question 27

What is the relative mass and charge of an Electron?

Answer 27

Relative mass: -1, Relative charge: -1 ## Footnote Electrons are negatively charged particles that orbit the nucleus.

Question 28

What does the atomic number represent?

Answer 28

Number of protons in an atom ## Footnote The atomic number determines the identity of the element.

Question 29

If an atom has 3 protons, how many electrons does it have?

Answer 29

3 electrons ## Footnote Atoms are generally neutral, so the number of protons equals the number of electrons.

Question 30

What is the formula to calculate the number of neutrons in an atom?

Answer 30

Relative atomic mass - Proton number ## Footnote This calculation helps determine the number of neutrons present in the nucleus.

Question 31

What is the radius of a typical atom?

Answer 31

0.1 nm (1x10^-10 m) ## Footnote This size is significantly larger than the nucleus, which is much smaller.

Question 32

What is the radius of the nucleus compared to the atom?

Answer 32

Less than 1/10,000th of the atom (1x10^-14 m) ## Footnote This shows that the nucleus is extremely small in relation to the overall size of the atom.

Question 33

What is the key atomic symbol for Carbon?

Answer 33

C ## Footnote Carbon is a fundamental element in organic chemistry.

Question 34

What does the relative atomic mass indicate?

Answer 34

The mass of an atom relative to other atoms ## Footnote It is often compared to the mass of carbon-12.

Question 35

True or False: The mass of an atom is made up of protons and neutrons.

Answer 35

True ## Footnote Electrons contribute negligibly to the mass of an atom.

Question 36

Fill in the blank: An atom likes to be overall _______.

Answer 36

neutral ## Footnote This neutrality is achieved when the number of protons equals the number of electrons.

Question 37

What is the relationship between the number of protons and neutrons in an atom?

Answer 37

They are not necessarily equal ## Footnote The number of neutrons can vary even for atoms of the same element (isotopes).

Question 38

How many neutrons are in a Chlorine atom with a relative atomic mass of 35 and 17 protons?

Answer 38

18 neutrons ## Footnote Calculation: 35 (relative atomic mass) - 17 (proton number) = 18.

Question 39

How many neutrons are in a Potassium atom with a relative atomic mass of 39 and 19 protons?

Answer 39

20 neutrons ## Footnote Calculation: 39 (relative atomic mass) - 19 (proton number) = 20.

Question 40

What is the relative atomic mass of Hydrogen?

Answer 40

1 ## Footnote Hydrogen has a relative atomic mass of approximately 1.

Question 41

What is the electron configuration of Carbon?

Answer 41

2, 4 ## Footnote Carbon has 6 electrons, with 2 in the first shell and 4 in the second.

Question 42

What is the electron configuration of Chlorine?

Answer 42

2, 8, 7 ## Footnote Chlorine has 17 electrons, with 2 in the first shell, 8 in the second, and 7 in the third.

Question 43

What is the maximum number of electrons in the first shell?

Answer 43

2 ## Footnote The first shell can hold a maximum of 2 electrons. ELECTRONS ORBIT THE NUCLEUS AT SET DISTANCES

Question 44

What is the maximum number of electrons in the second shell?

Answer 44

8 ## Footnote The second shell can hold a maximum of 8 electrons.

Question 45

What is the maximum number of electrons in the third shell?

Answer 45

8 ## Footnote The third shell can hold a maximum of 8 electrons.

Question 46

Fill in the blank: The first energy level can hold up to _______ electrons.

Answer 46

2

Question 47

Fill in the blank: Oxygen has an atomic number of 8. What is its electron configuration? _______.

Answer 47

2, 6

Question 48

What do protons, neutrons, and electrons represent in terms of charge and relative mass?

Answer 48

Protons: +1 charge, 1 mass unit; Neutrons: 0 charge, 1 mass unit; Electrons: -1 charge, negligible mass ## Footnote Protons have a positive charge, neutrons have no charge, and electrons have a negative charge.

Question 49

What does the mass number of an atom represent?

Answer 49

The total number of protons and neutrons ## Footnote The mass number indicates the mass of the atom.

Question 50

True or False: Overall, atoms have no net charge.

Answer 50

True ## Footnote Atoms are neutral because they have equal numbers of protons and electrons.

Question 51

Discuss why sodium is in group 1.

Answer 51

Sodium has one electron in its outer shell ## Footnote Elements in group 1 have similar chemical properties due to their single outer electron.

Question 52

Discuss why calcium and magnesium are in group 2.

Answer 52

Calcium and magnesium have two electrons in their outer shell ## Footnote Elements in group 2 have similar chemical properties due to their two outer electrons.

Question 53

What is the basic structure of an atom?

Answer 53

Nucleus with protons and neutrons, surrounded by electrons in shells ## Footnote The structure of an atom includes a central nucleus and orbiting electrons.

Question 54

What is the name of this table?

Answer 54

Periodic Table

Question 55

What does this image show?

Answer 55

Electronic configuration

Question 56

How do electrons orbit the nucleus?

Answer 56

At set distances in certain, fixed energy levels (shells) | 2,8,8 (the first 3 shells)

Question 57

Which element is hydrogen?

Answer 57

Element A | 1 electron only

Question 58

Which element is a halogen?

Answer 58

Element C | There are 10 electrons, therefore there are 10 protons. Neon has Atomic

Question 59

Which group A element is a metal

Answer 59

sodium (Na)