Science - Periodic table & reactions, Skills

What is a metalloid?

Elements where their properties are between those of metals and non-metals.

Describe the chemical properties of metal oxides

• Most are solids at 20°C

• They are basic

• If dissolved in water they form alkaline solutions

Physical properties of an element describe..

how a substance behaves generally.

Examples of physical properties:

• Conductor of electricity

• Dense

• Malleable

• Sonorous

• High melting point

Chemical properties describe…

how a substance behaves in terms of its chemical structure.

Examples of chemical properties:

• How reactive it is

• What other substances it reacts with

• What products it produces in reactions

Properties of the Alkali Metals:

• Very reactive

• React vigorously with water

• Lower melting points than most other metals

• Soft

• Low density

• Low melting point

What happens to reactivity and melting points as you go down group 1?

They get more reactive and melting point decreases.

Properties of The Halogens:

Very reactive

Opposite of group 1

What happens to reactivity and melting points as you go down group 7?

Melting point increases and reactivity decreases.

What is a displacement reaction?

An element from higher up in the group takes the place of one from lower.

Explain noble gases reactivity and boiling points

Very unreactive. Low boiling points, so they are gases are room temperature. Boiling points increase as you go down the group.

The periodic table is organised by their..

chemical properties and physical properties.

To find the number of neutrons in an atom you need to..

subtract the atomic number from the atomic mass.

In an ion the number of electrons is ______ to the number of protons.

not equal

Describe the trend in reactivity as you go down group 7

As you go down the group, the reactivity decreases because it becomes harder to attract an extra electron.

We use a line graph if..

Both variables are continuous.

We use a bar chart if..

One of the variables is categorical.

List the 6 steps of the scientific method

1. Observation

2. Question

3. Hypothesis

4. Prediction

5. Test

6. Analyse

How do we know when data is directly proportional?

If the graph would come out as a straight line through the origin or if the numbers in the table double in both columns.

Repeatable

Readings are repeated and are close together.

Reliability

How much you can trust the results. More so by repeating the investigation.

Systematic error

Errors that affect all results by the same amount.

Random error

Errors that affect just one or two results - usually a measuring mistake

State the colours of each element in group 7:

Bromine = Red-brown

Chlorine = Yellow-green

Iodine = Grey

Fluorine = Yellow

Astatine = Black

Describe what you would see when Alkali Metals react with water

They react vigorously with water and produce a metal hydroxide and hydrogen gas (fizzing).

What materials would you use to build a boat?

Aluminium and iron because they have a low density so they’re light weight and suitable for floating.

What is the density trend of the halogens and alkali metals as you go down the group?

They increase as you go down the group.

When does corrosion happen?

Corrosion happens when metal atoms react with oxygen at the surface of the metal to form a layer of metal oxide.

Corrosion of metals can be prevented by..

coating them as this excludes oxygen in the air.

Where can transition metals be found on the periodic table?

They are located in the middle section of the periodic table.