SME
Grade 7 Science · Physical Science
Atoms, elements and molecules
Build molecules from atoms, and tell elements, compounds and mixtures apart by what they are made of.
Explore
Two hydrogen atoms joined to one oxygen atom: H₂O.
It is a compound: two kinds of atom in every molecule.
Assumptions
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Everything is made of atoms: about 100 kinds, one for each element.
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A molecule is two or more atoms joined together. Water is two hydrogen atoms joined to one oxygen atom.
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The colors are the classroom ones: hydrogen white, carbon black, oxygen red, nitrogen blue.
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Choose a substance to see its particles.
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.