Atoms, Elements & Compounds
CONCEPTUALExplain the differences between atoms, elements, and compounds; describe the simple Bohr model of the atom (nucleus with protons and neutrons, electrons in shells); and write and interpret chemical symbols and simple formulae
Mastery Evidence
- Defines atom, element, and compound and distinguishes between them with examples
- Draws a simple Bohr model of an atom labelling nucleus (protons/neutrons) and electron shells
- Reads a chemical formula to identify the elements and number of each atom (e.g. H₂O, CO₂, NaCl)
- Identifies the difference between a mixture and a compound
Assessment Prompt
“If [child] saw the formula H₂O on a label, could they explain what it means — which atoms are involved, how many of each, and why water is a compound rather than just a mixture of hydrogen and oxygen?”
Curriculum Standards4 alignments
MS-PS1-1Next Generation Science Standards (NGSS) Middle Schoolcodes onlyKS3.Sci.Chem.AEC.1The national curriculum in Englanda simple (Bohr) model of the atom
KS3.Sci.Chem.AEC.2The national curriculum in Englandthe differences between atoms, elements and compounds
KS3.Sci.Chem.AEC.3The national curriculum in Englandchemical symbols and formulae for elements and compounds
Prerequisites1
- The Particle ModelhardAges 11—12
Show full prerequisite tree
- The Particle Model hard
Atoms and molecules are the particles referred to in the particle model — builds directly on it
- Drawing Particle Diagrams hard
Using the particle model to explain density, compressibility, and anomalous expansion requires fluent reading and drawing of particle diagrams
- Matter Is Made of Particles hard
KS3 particle model extends US KS2 introduction to matter as particles too small to see
- Drawing Particle Diagrams hard
Developing a model of matter as particles too small to see is built on the particle diagram representation
- Heating & Cooling Changes hard
Must observe state changes before explaining them with particle model
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
- Solids, Liquids & Gases hard
Must understand observable states of matter before modelling them with particles
- States of Matter Vocabulary hard
Comparing and grouping materials as solids, liquids, or gases requires the naming vocabulary for the three states
- Drawing Particle Diagrams hard
Comparing and grouping solids, liquids, and gases by properties is greatly aided by the particle diagram representation
- Heating & Cooling Changes hard
Must classify states of matter before understanding changes between states
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
- Grouping Materials hard
Must group materials by properties before classifying into three states of matter
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Changing Shapes of Solids soft
Changing shapes of solids provides context for understanding solid properties
- Describing Material Properties hard
Must know material properties before investigating how shapes change
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Solids, Liquids & Gases hard
KS3 particle model extends KS2 classification of solids, liquids and gases by observable properties
- States of Matter Vocabulary hard
Comparing and grouping materials as solids, liquids, or gases requires the naming vocabulary for the three states
- Drawing Particle Diagrams hard
Comparing and grouping solids, liquids, and gases by properties is greatly aided by the particle diagram representation
- Heating & Cooling Changes hard
Must classify states of matter before understanding changes between states
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
- Grouping Materials hard
Must group materials by properties before classifying into three states of matter
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Changing Shapes of Solids soft
Changing shapes of solids provides context for understanding solid properties
- Describing Material Properties hard
Must know material properties before investigating how shapes change
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
Unlocks6
- Physical vs Chemical ChangeshardAges 11—13
- Acids, Alkalis & pHsoftAges 12—13
- Radiometric DatingsoftAges 11—13
- Where Elements Come FromsoftAges 12—14
- Pure Substances & MixtureshardAges 11—13
- The Periodic TablehardAges 11—12