GCSE CHEMISTRY: Atomic Structure and the Periodic Table

What is the charge of a proton?

+1

What is the charge of a neutron

0

What is the charge of an electron

-1

Where are protons found in an atom

In the nucleus

Where are electrons found in the atom

In the shells

What is the mass number and what does it tell you?

The mass number is the big number and it tells us the number of protons and neutrons.

What is the atomic number and what does it tell you?

The atomic number is the small number and it tells us the number of protons.

What is an isotope

An isotope are atoms of the same elements with the same number of protons and different numbers of neutrons.

Who proposed the solid sphere theory and when

John Dalton in the 1800s

Who came up with the plum pudding theory and when

JJ Thompson in 1897

What does the plum pudding theory suggest.

An atom must contain negative charges (electrons)

Who created the nuclear model and when

Ernest Rutherford in 1909

What experiment did Rutherford carry out and what did it show?

Rutherford fired alpha particles at gold foil, revealing that an atom's mass is concentrated in its center, with gaps around it.

Who discovered the neutron

James Chadwick

Who came up with the Quantum (Bohr) Model and when

Neils Bohr in 1913

What did Bohr propose about electrons

Electrons orbit the nucleus in fixed shells.

Why was Bohr’s model accepted

It was supported by experimental observations.

What is the maximum number of electrons in the first shell

2

How many electrons can the second and third shells hold

8

How are electrons arranged in an atom

They arranged in shells that orbit the nucleus

What determines the chemical properties of an element

The number of electrons in the outer shell

What is an ion

An atom with a charge

How doe an atom become a positive ion

By losing 1 or more electrons

How does an atom become a negative ion

By gaining 1 or more electron

How are elements arranged in the modern periodic table

They’re arranged by properties

What is a group in the periodic table

(Columns) Number of electrons in the outermost shell

What is a period in the periodic table

(Rows) The number of shells an element has

What do elements in the same group have in common

They have the same number of electrons in the outer shell.

What are Group 0 elements also known as

Noble Gases

Why do Group 0 elements not react

They have a full outer shell

What is the trend in boiling points down Group 1

The boiling points increase as you go down

Why are Noble Gases used in balloons and lighting

They are unreactive

Why do Noble Gases exist as single atoms

They don’t make compounds because they’re unreactive

Why do Group 1 metals get more reactive as you go down the group

Negative outer electrons are further away from the positive nucleus meaning they are more easily lost

What happens when Group 1 metals react with water

They react violently

What gas is produced when Group 1 metals react with water

Hydrogen

What solution is formed when Group 1 metals react with water

Alkaline solution

Why are Group 1 metals stored in oil

So they don’t react with oxygen

What is the trend in melting points of Group 1 metals as you go down the group

The melting points decrease

What type of molecule do halogens form

Diatomic molecules

What is a displacement reaction

The more reactive element takes the place of the less reactive element

Which halogens is the most reactive

Fluorine

What happens when a more reactive halogen meets a less reactive halide solution

Halide loses outer shell electrons halogen gains outer shell electrons

Why do Halogens form -1 ions

They have 7 electrons in their outer shells and need 1 more for a full outer shell.

Why do Group 7 elements get less reactive as they go down the group

Increasing the proton number means an electron is more easily lost.

What are Group 7 elements also known as

Halogens

Do metals gain or lose electrons when forming ions

Lose electrons

Do non-metals gain or lose electrons when forming ions

Gain electrons

Why are metals good conductors

Their electrons can flow easily

Why are non-metals brittle

Their electrons are more fixed

Where are transition metals found in the periodic table

In the middle

Give 1 property of transition metals

Conductivity

Why are transition metals useful as catalysts?

They can easily lose or gain electrons, allowing them to temporarily bond with reactants without being used up.

How do transition metals compare to Group 1 metals in reactivity

Less reactive

Why do transition metals form colored compounds?

They have partially filled d-orbitals that absorb certain wavelengths of light, resulting in color.