Atoms, elements and compounds
Every substance around you is built from around 100 kinds of atom, combined in patterns represented by neat chemical shorthand.
Part of your national curriculum
- Chemistry: the particulate nature of matter: Understand atoms, elements and compounds, and the use of chemical symbols and formulae
Lesson overview
What you'll learn in this lesson
Understand atoms, elements and compounds, and the use of chemical symbols and formulae
Key learning points
- • Atoms and elements
- • Compounds
- • Symbols and formulae
This lesson at a glance
- 26 minutes
- 17 parts to scroll through
- 3 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 17
Visual introductionPicture this
Atoms, elements and compounds
Every substance around you is built from around 100 kinds of atom, combined in patterns represented by neat chemical shorthand.
In a nutshell
Understand atoms, elements and compounds, and the use of chemical symbols and formulae
Learning cycle
Part 2 of 17
Learning cycle 1 of 2
Part 1 · Atoms and elements
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 17
Learn
Atoms and elements
An atom is the smallest part of an element that still has the properties of that element. An element is a substance made of only one type of atom — for example, oxygen (O) or iron (Fe). There are about 118 known elements, listed on the periodic table.
Reset break
Part 4 of 17
Pause
That's sitting 1 of 4 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Explore the idea
Part 5 of 17
Learn
Compounds
A compound forms when two or more different elements chemically combine in fixed proportions, creating a new substance with different properties from its elements. Water (H2O) is a compound of hydrogen and oxygen; sodium chloride (NaCl) is a compound of sodium and chlorine.
Quick check
Part 6 of 17
Quick check
Part 7 of 17
Reset break
Part 8 of 17
Pause
That's sitting 2 of 4 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Learning cycle
Part 9 of 17
Learning cycle 2 of 2
Part 2 · Symbols and formulae
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 10 of 17
Learn
Symbols and formulae
Each element has a one- or two-letter chemical symbol, for example C for carbon and Mg for magnesium. A chemical formula shows the ratio of atoms in a compound: CO2 means each molecule has 1 carbon atom and 2 oxygen atoms.
Quick check
Part 11 of 17
Quick check
Why is water's formula different from a mixture of hydrogen and oxygen gas?
Reset break
Part 12 of 17
Pause
That's sitting 3 of 4 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Challenge round
Part 13 of 17
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Challenge round
Part 14 of 17
Game · Fill the gaps
Finish the sentences
Choose the word that belongs in each gap.
There are about 118 known ____, listed on the periodic table.
Each element has a one- or two-letter ____ symbol, for example C for carbon and Mg for magnesium.
Challenge round
Part 15 of 17
Game · Recall cards
What is an element?
Card 1 of 4
Mastery quiz
Part 16 of 17
Marked quiz
End of lesson quiz: Atoms, elements and compounds
4 questions, marked with the reasoning shown. No timer.
1. What is an element?
2. What does the formula H2O tell you?
3. Why is water's formula different from a mixture of hydrogen and oxygen gas?
4. A compound is
Lesson round-up
Part 17 of 17
Lesson round-up
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Understand atoms, elements and compounds, and the use of chemical symbols and formulae