Chapter 5: Matter - Knowledge Organiser

A set of 10 question-and-answer flashcards covering key concepts from Chapter 5: Matter, including elements, compounds, polymers, and trends in the Periodic Table.

What is an element and where is it found?

An element is a substance that only contains one type of atom, and it is found on the Periodic Table.

In chemical naming, what is the rule for a compound consisting of a metal and a non-metal?

The metal is mentioned first without changing its name, while the name of the non-metal is changed, such as oxygen changing to oxide.

What does the small number in a chemical formula like $CH_4$ or $CO_2$ represent?

The small number tells us the number of each element which is in front of the number.

How are groups and periods arranged on the Periodic Table?

Groups are the columns that go downwards, and periods are the rows that go sideways.

What are polymers and what are the two main types?

Polymers are long chains of groups of atoms which are repeated many times; they can be natural (wool, cotton, starch, rubber) or synthetic (polythene, polystyrene, nylon).

What is the reactivity trend for Group 0 elements and what happens when electricity is passed through them?

All Group 0 elements are unreactive, and when electricity is passed through the gas, they emit a brightly coloured light.

What products are formed when Group 1 elements react with water?

Group 1 elements react with water to form alkali solutions following the equation: $\text{metal} + \text{water} \rightarrow \text{metal hydroxide} + \text{hydrogen}$.

What physical properties characterize Group 1 alkali metals compared to other metals?

Group 1 metals are much softer than other metals and have much lower melting and boiling points.

What is a displacement reaction in the context of Group 7 elements?

A displacement reaction is where a more reactive halogen will take the place of a less reactive halogen in a compound.

What is the trend for melting and boiling points in Group 7 (the halogens) as you move down the group?

Moving down the group, the elements have an increased melting and boiling point.