1.2 The Periodic Table

These flashcards are for Topic 1 - Atomic Structure & The Periodic Table in AQA GCSE Chemistry (Triple Higher). They cover specification points 4.1.2.1 - 4.1.2.6.

In the modern periodic table, what are the vertical columns of elements called?

Groups

In the modern periodic table, what are the horizontal rows of elements called?

Periods

Elements are arranged in the modern periodic table in order of increasing _______ _________.

atomic number

What do elements in the same group of the periodic table have in common regarding their electron structure?

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

What do elements in the same period of the periodic table have in common regarding their electron structure?

They have the same number of electron shells.

Why is the periodic table so named?

Because elements with similar properties occur at regular intervals.

Who created an early version of the periodic table in 1869, arranging elements by atomic weight and leaving gaps for undiscovered elements?

Dmitri Mendeleev

Mendeleev overcame issues in his periodic table by leaving _____ for elements he predicted were not yet discovered.

gaps

Why did Mendeleev swap the positions of iodine and tellurium in his periodic table, despite tellurium having a higher atomic weight?

To make iodine line up with other elements that had similar chemical properties (chlorine and bromine).

The existence of what atomic feature explains the 'pair reversals' (like iodine and tellurium) in Mendeleev's atomic weight-based table?

Isotopes

John Newlands arranged elements in order of atomic weight and noticed similar properties occurred every eighth element, which he called the 'law of _______'.

octaves

Where are metals generally found on the periodic table?

On the left of the stepped line and towards the bottom.

Where are non-metals generally found on the periodic table?

On the right of the stepped line and towards the top.

What type of ions do metal atoms typically form when they react?

Positive ions (by losing electrons)

What type of ions do non-metal atoms typically form when they react?

Negative ions (by gaining electrons)

What is the name for the elements in Group 0 of the periodic table?

The noble gases

Why are the noble gases (Group 0) unreactive or inert?

They have a full outer shell of electrons, which is a stable arrangement.

What is the trend in boiling points for the noble gases as you go down Group 0?

The boiling points increase

Why do the boiling points of noble gases increase down the group?

The atoms become larger, leading to stronger intermolecular forces that require more energy to overcome.

What is the name for the elements in Group 1 of the periodic table?

The alkali metals

How many electrons do Group 1 elements have in their outer shell?

One

Describe three physical properties typical of alkali metals.

They are soft, have low densities, and have relatively low melting points.

What is the trend in melting points for the alkali metals as you go down Group 1?

The melting points decrease

What is the trend in reactivity for the alkali metals as you go down Group 1?

The reactivity increases

Why does reactivity increase as you go down Group 1?

The outer electron is further from the nucleus, attraction decreases and shielding increases and it is lost more easily.

What are the two products formed when an alkali metal reacts with water?

A metal hydroxide and hydrogen gas

What observation indicates that an alkaline solution is formed when a Group 1 metal reacts with water?

Universal indicator turns blue or purple

Describe the observation when potassium is added to water.

It burns violently with a lilac flame, melts into a ball, and disappears rapidly, often with a small explosion.

What is the product when a Group 1 metal reacts with chlorine?

A metal chloride (a white solid)

Write the balanced chemical equation for the reaction of sodium with chlorine.

2Na + Cl₂ → 2NaCl

What is formed when an alkali metal reacts with oxygen?

A metal oxide

What is the name for the elements in Group 7 of the periodic table?

The halogens

How many electrons do Group 7 elements have in their outer shell?

Seven

Halogen elements exist as ___________ molecules, where atoms are joined in pairs.

diatomic

What is the state of chlorine at room temperature?

A pale green gas

What is the state of bromine at room temperature?

A brown liquid

What is the state of iodine at room temperature?

A purple-black solid

What is the trend in melting and boiling points for the halogens as you go down Group 7?

The melting and boiling points increase

Why do the melting and boiling points of halogens increase down the group?

The molecules become larger, leading to stronger intermolecular forces that require more energy to overcome.

What is the trend in reactivity for the halogens as you go down Group 7?

The reactivity decreases

Why does reactivity decrease as you go down Group 7?

The outer shell is further from the nucleus, making it harder for the atom to gain an electron due to decreased attraction and increased shielding.

When a halogen reacts with a metal, what type of compound is formed?

An ionic compound (a salt)

When a halogen atom gains an electron to form a 1- ion, it is called a _________.

halide

What is a displacement reaction in the context of halogens?

A reaction where a more reactive halogen displaces a less reactive halogen from an aqueous solution of its salt.

Complete the word equation: chlorine + potassium iodide → ?

potassium chloride + iodine

Would bromine displace chlorine from a solution of sodium chloride? Explain why.

No, because bromine is less reactive than chlorine.

Where are the transition elements located in the periodic table?

In the central block, between Group 2 and Group 3.

Most metal oxides are described as chemically ______.

basic

Most non-metal oxides are described as chemically _______.

acidic

The ability of a metal to be bent or hammered into shape without snapping is called ___________.

malleability

A non-metal, when solid, is typically ________, meaning it breaks easily.

brittle

When halogens react with other non-metals, such as hydrogen, they form _________ compounds.

covalent

What is the name of the compound formed when hydrogen reacts with chlorine?

Hydrogen chloride (HCl)

What is formed when a hydrogen halide gas, like HCl(g), dissolves in water?

An acidic solution

The electronic structure of the atoms of five elements are shown in the figure.

The letters are not the symbols of the elements.

Which element is hydrogen?

B

The electronic structure of the atoms of five elements are shown in the figure.

The letters are not the symbols of the elements.

Which element is a halogen?

D

The electronic structure of the atoms of five elements are shown in the figure.

The letters are not the symbols of the elements.

Which element is a metal in the same group of the periodic table as element A?

E

The electronic structure of the atoms of five elements are shown in the figure.

The letters are not the symbols of the elements.

Which element exists as single atoms?

C

Five elements, V, W, X, Y and Z, are shown in the periodic table.

The letters are not the chemical symbols of the five elements.

Which element is a transition metal?

Y

Five elements, V, W, X, Y and Z, are shown in the periodic table.

The letters are not the chemical symbols of the five elements.

Which element is in Group 2?

W

Five elements, V, W, X, Y and Z, are shown in the periodic table.

The letters are not the chemical symbols of the five elements.

Which element is a noble gas?

V

Five elements, V, W, X, Y and Z, are shown in the periodic table.

The letters are not the chemical symbols of the five elements.

Which element has an atomic (proton) number of 4?

W

Five elements, V, W, X, Y and Z, are shown in the periodic table.

The letters are not the chemical symbols of the five elements.

Which element forms only 1+ ions?

X

The diagram shows the chemical symbols of five elements in the periodic table.

Choose the correct chemical symbol to complete the sentence.

The element that is an alkali metal is __________.

Na

The diagram shows the chemical symbols of five elements in the periodic table.

Choose the correct chemical symbol to complete the sentence.

The element that is a transition metal is ________.

Cu

The diagram shows the chemical symbols of five elements in the periodic table.

Choose the correct chemical symbol to complete the sentence.

The element in Group 4 is ___________.

C

The diagram shows the chemical symbols of five elements in the periodic table.

Choose the correct chemical symbol to complete the sentence.

The element with a full outer energy level (shell) of electrons is _________.

He

The diagram shows the chemical symbols of five elements in the periodic table.

Which other element goes in the shaded box?

Hydrogen

This question is about the periodic table of elements.

In 1869 Dmitri Mendeleev produced an early version of the periodic table.

Choose the correct answer from the box to complete this sentence.

Mendeleev first arranged the elements in order of their ___________________.

atomic weight

This question is about the periodic table of elements.

In 1869 Dmitri Mendeleev produced an early version of the periodic table.

Choose the correct answer from the box to complete this sentence.

Mendeleev then placed elements with similar properties in columns called _____________.

groups

This question is about the periodic table of elements.

In 1869 Dmitri Mendeleev produced an early version of the periodic table.

Choose the correct answer from the box to complete this sentence.

When the next element did not fit the pattern, Mendeleev ___________________.

left a gap

This question is about the periodic table of elements.

In 1869 Dmitri Mendeleev produced an early version of the periodic table.

Choose the correct answer from the box to complete this sentence.

Mendeleev was not able to include the noble gases (Group 0) in his periodic table, because the noble gases __________________.

has not been discovered by 1869

Use the correct word from the box to complete each sentence.

In the modern periodic table elements are arranged in order of the number of _________________ in their nucleus.

Elements in the same group have the same number of ________________ in their highest energy level (outer shell).

protons, electrons

Chlorine, bromine and iodine are in Group 7 of the periodic table.

Complete the word equation for the reaction between chlorine and sodium bromide.

chlorine + sodium bromide → ____________ + ___________ _________

bromine, sodium chloride

Chlorine, bromine and iodine are in Group 7 of the periodic table.

Why does iodine not react with sodium bromide solution?

Iodine is less reactive than bromine, so it will not displace it from an aqueous solution of its salt.

A chemistry teacher demonstrated the reaction between sodium and water to a class of students.

One of the students wrote the following notes.

Use the information in the box to help you answer these questions.

What evidence is there that: sodium has a low melting point

The sodium melted quickly to give a silvery ball.

A chemistry teacher demonstrated the reaction between sodium and water to a class of students.

One of the students wrote the following notes.

Use the information in the box to help you answer these questions.

What evidence is there that: sodium is soft

A piece of sodium was cut easily into smaller pieces with a knife.

A chemistry teacher demonstrated the reaction between sodium and water to a class of students.

One of the students wrote the following notes.

Use the information in the box to help you answer these questions.

What evidence is there that: a gas was produced?

The sodium fizzed.