Year 8 Atoms, Elements and Compounds Worksheet - Beginner

Year 8 Atoms, Elements and Compounds worksheet for Year 8 (Key Stage 3 / Year 7-9 (Ages 11-14)). Beginner level science practice, aligned to the UK National Curriculum. Print-ready with answer key included.

Science•Key Stage 3 / Year 7-9 (Ages 11-14)•Atoms, Elements and Compoundsbeginner

23 views

Atoms, Elements and Compounds: The Building Blocks of Matter

Year 8 Science | Ages 12–13 | Beginner

Name:

Date:

Score:

Instructions: Work through each activity in order. Use the examples and word bank to help you, and write answers in the boxes. Read each formula carefully: the small numbers show how many atoms of each element are present.

Atoms, Elements and Compounds

Use the word bank to complete each definition. An element contains one type of atom; a compound contains atoms of different elements chemically joined. Choose the best term for each sentence.

Word bank: atom, element, compound

1. The smallest particle of an element that still has the properties of that element is an ___.

2. A substance made from only one type of atom is an ___.

3. A substance made from atoms of two or more different elements chemically joined is a ___.

4. Is water (H₂O) an element or a compound?

Chemical Symbols and Formulae

Use the symbol clues to complete the formula questions. A formula shows which elements are present and how many atoms of each there are. For example, CO₂ contains one carbon atom and two oxygen atoms.

1. Write the chemical symbol for oxygen.

2. How many hydrogen atoms are shown in H₂O?

3. Which two elements are present in CO₂?

4. How many atoms are there altogether in one molecule of H₂O?

5. Is O₂ an element or a compound?

Reading the Periodic Table

Use the information in the table and your knowledge of the periodic table. A group is a vertical column; a period is a horizontal row. Answer each question in the box.

Element	Symbol	Group	Period
Sodium	Na	1	3
Magnesium	Mg	2	3
Carbon	C	14	2
Chlorine	Cl	17	3

1. Which element in the table is in Group 14?

2. Which two listed elements are in Period 3?

3. What is the symbol for magnesium?

4. Is chlorine a metal or a non-metal?

Comparing Metals and Non-metals

Choose the best answer for each question. Think about typical properties: metals are often shiny, conduct heat and electricity, and can be bent or shaped. Many non-metals are dull and are poor conductors.

1. Which property is typical of many metals?

2. Which material is usually a non-metal?

3. A material can be hammered into thin sheets. Which property does this describe?

4. Which statement about non-metals is generally correct?

Dalton’s Model of the Atom

John Dalton proposed an early scientific model of matter. Use the word bank to complete the statements. Dalton pictured atoms as tiny solid spheres and suggested that each element had its own type of atom.

Word bank: atoms, solid, different, elements

1. Dalton suggested that all matter is made of tiny particles called ___.

2. In Dalton’s model, an atom was a tiny, indivisible ___ sphere.

3. Dalton proposed that atoms of ___ elements were different from one another.

4. A substance made from one type of atom is an ___.

Put the Ideas Together

Use what you have learnt about atoms, formulae and compounds. Explain your reasoning briefly where the question asks you to describe or compare. Keep each answer focused.

1. A particle contains two hydrogen atoms chemically joined to one oxygen atom. Write its chemical formula.

2. Is carbon dioxide (CO₂) an element or a compound? Give one reason.

3. Name one typical property of a metal and one typical property of a non-metal.

4. Sodium is in Group 1 and Period 3. What does “Period 3” tell you about sodium’s position in the periodic table?

Answer Key

Activity 1: 1. atom ; 2. element ; 3. compound ; 4. compound

Activity 2: 1. O ; 2. 2 ; 3. carbon and oxygen ; 4. 3 ; 5. element

Activity 3: 1. Carbon ; 2. Sodium and magnesium ; 3. Mg ; 4. non-metal

Activity 4: 1. Good electrical conduction ; 2. Sulfur ; 3. Malleability ; 4. Many are poor conductors of electricity

Activity 5: 1. atoms ; 2. solid ; 3. different ; 4. element

Activity 6: 1. H₂O ; 2. Compound, because it contains carbon and oxygen chemically joined ; 3. Example: a metal conducts electricity; a non-metal is often a poor electrical conductor ; 4. It is in the third horizontal row of the periodic table